Extended-interval gentamicin administration in neonates: a simplified approach.

OBJECTIVE: Gentamicin dosing is highly variable and remains complicated in the neonatal population. Traditional dosing in our unit resulted in an excessive number of elevated trough serum gentamicin levels. We hypothesized that one uniform gentamicin dose for neonates of all gestational ages will reduce the incidence of elevated trough levels from 50 to 10%. STUDY DESIGN: Our prospective, randomized, controlled trial enrolled eligible neonates into two groups, according to gestational age (⩽34 6/7 (group I) and >35 0/7 weeks (group II)). Patients in the study arm received a dose of gentamicin 5 mg kg(-1) intravenous (i.v.) every 36 h, whereas patients in the control arm received traditional dosage. Patients were monitored for resolution of infection, serum gentamicin levels and adverse effects. We confirmed our findings in a follow-up study. Fisher's exact and Mann-Whitney tests were used for statistical analysis. RESULTS: We enrolled 96 neonates, 50 in group I (n=25 per arm) and 46 in group II (n=23 per arm). Elevated trough levels were reduced by 66% in group I (P=0.61) and 100% in group II (P=0.0015). In the study arm of both groups, 48/49 neonates had Cmin serum gentamicin concentration (SGC) <2 mg l(-1) and the majority had a trough SGC <1 mg l(-1) (P<0.0001). The study dose resulted in maximum gentamicin levels in the goal range and a 50% reduction in dosage modifications. There were no treatment failures or adverse effects. Our follow-up study phase confirmed these results. CONCLUSION: A standardized gentamicin dosage of 5 mg kg(-1) i.v. every 36 h to neonates of all gestational ages was safe and resulted in SGCs in goal therapeutic ranges. The implications of this simplified gentamicin dosage are to reduce health-care costs by less frequent dosing of gentamicin and reducing medication errors in physician prescribing from complicated dosing schemes.

Cyanogenic glucosides in grapevine: polymorphism, identification and developmental patterns.

Twelve grapevine (Vitis vinifera L.) cultivars were surveyed for 'cyanide potential' (i.e. the total cyanide measured in beta-glucosidase-treated crude, boiled tissue extract) in mature leaves. Two related cultivars (Carignan and Ruby Cabernet) had mean cyanide potential (equivalent to 110 mgHCNkg-1fr.wt) ca. 25-fold greater than that of the other 10 cultivars, and so the trait is polymorphic in the species. In boiled leaf extracts of Carignan and Ruby Cabernet, free cyanide constituted a negligible fraction of the total cyanide potential because beta-glucosidase treatment was required to liberate the major cyanide fraction - which is therefore bound in glucosylated cyanogenic compound(s) (or cyanogenic glucosides). In addition, cyanide was liberated from ground leaf tissue of Ruby Cabernet but not Sultana (a cultivar with low cyanide potential). Hence, the high cyanide potential in Ruby Cabernet leaves is coupled with endogenous beta-glucosidase(s) activity and this cultivar may be considered 'cyanogenic'. A method was developed to detect and identify cyanogenic glucosides using liquid chromatography combined with tandem mass spectrometry (LC-MS/MS). Two putative cyanogenic glucosides were found in extracts from leaves of Carignan and Ruby Cabernet and were identified as the epimers prunasin and sambunigrin. Cyanide potential measured at three times over the growing season in young and mature leaves, petioles, tendrils, flowers, berries, seeds and roots of Ruby Cabernet was substantially higher in the leaves compared with all other tissues. This characterisation of cyanogenic glucoside accumulation in grapevine provides a basis for gauging the involvement of the trait in interactions of the species with its pests and pathogens.

Chimerism in grapevines: implications for cultivar identity, ancestry and genetic improvement.

In the course of DNA profiling of grapevine cultivars using microsatellite loci we have occasionally observed more than two alleles at a locus in some individuals and have identified periclinal chimerism as the source of such anomalies. This phenomenon in long-lived clonally propagated crops, such as grapevine, which contains historically ancient cultivars, may have a role in clonal differences and affect cultivar identification and pedigree analysis. Here we show that when the two cell layers of a periclinal chimera, Pinot Meunier, are separated by passage through somatic embryogenesis the regenerated plants not only have distinct DNA profiles which are different from those of the parent plant but also have novel phenotypes. Recovery of these phenotypes indicates that additional genetic differences can exist between the two cell layers and that the Pinot Meunier phenotype is due to the interaction of genetically distinct cell layers. It appears that grapevine chimerism can not only modify phenotype but can also impact on grapevine improvement as both genetic transformation and conventional breeding strategies separate mutations in the L1 and L2 cell layers.

Consequences of transferring three sorghum genes for secondary metabolite (cyanogenic glucoside) biosynthesis to grapevine hairy roots.

A multigenic trait (biosynthesis of the secondary metabolite, dhurrin cyanogenic glucoside) was engineered de novo in grapevine (Vitis vinifera L.). This follows a recent report of transfer of the same trait to Arabidopsis (Arabidopsis thaliana) using three genetic sequences from sorghum (Sorghum bicolor): two cytochrome P450-encoding cDNAs (CYP79A1 and CYP71E1) and a UDPG-glucosyltransferase-encoding cDNA (sbHMNGT). Here we describe the two-step process involving whole plant transformation followed by hairy root transformation, which was used to transfer the same three sorghum sequences to grapevine. Transgenic grapevine hairy root lines that accumulated transcript from none, one (sbHMNGT), two (CYP79A1 and CYP71E1) or all three transgenes were recovered and characterisation of these lines provided information about the requirements for dhurrin biosynthesis in grapevine. Only lines that accumulated transcripts from all three transgenes had significantly elevated cyanide potential (up to the equivalent of about 100 mg HCN kg(-1) fresh weight), and levels were highly variable. One dhurrin-positive line was tested and found to release cyanide upon maceration and can therefore be considered 'cyanogenic'. In in vitro dual co-culture of this cyanogenic hairy root line or an acyanogenic line with the specialist root-sucking, gall-forming, aphid-like insect, grapevine phylloxera (Daktulosphaira vitifoliae, Fitch), there was no evidence for protection of the cyanogenic plant tissue from infestation by the insect. Consistently high levels of dhurrin accumulation may be required for this to occur. The possibility that endogenous grapevine gene expression is modulated in response to engineered dhurrin biosynthesis was investigated using microarray analysis of 1225 grapevine ESTs, but differences in patterns of gene expression associated with dhurrin-positive and dhurrin-negative phenotypes were not identified.

Congenital bronchiolo-alveolar airway malformation in a cynomolgus macaque (Macaca fascicularis).

Pulmonary congenital anomalies in animals are rare. Previously reported malformations include accessory lung formation, pulmonary hypoplasia, pulmonary agenesis, and various forms of hamartoma. Congenital bronchiolo-alveolar airway malformation, a new entity, is described in a 1-day-old male cynomolgus macaque. This neonate experienced breathing difficulties shortly after birth and died while therapy was being administered. Grossly, the right lung was markedly increased in size, firm, and pink. Histopathologically, sections of right lung showed irregular bronchiole-like and alveolus-like structures. There was marked widening of alveolar septae by loosely arranged mesenchymal cells and many centrally located capillaries. Alveoli were lined by cuboidal epithelial cells. There were scattered islands of immature cartilage. A grossly enlarged lung containing bronchiole-like and alveolus-like structures, immature cartilage islands, and many capillaries within alveolar septae on histopathologic examination, is inconsistent with previously described congenital pulmonary anomalies in animals and humans.

The strategic advantage: decision support through EIS (executive information systems).

Increasing pressures from a variety of sources are tightening the bottom line for hospital executives and managers. Decision support systems have to be developed to cope with a radically changing healthcare market.

Pulmonary capillaritis.

Vasculitis, inflammation, and necrosis of blood vessels can involve any size or type of vessel in the pulmonary vasculature, including the capillaries, so-called capillaritis. Although pulmonary capillaritis is a histopathologic diagnosis that is not pathognomonic of a specific disorder, it usually signals the presence of an underlying systemic vasculitis or collagen vascular disease. Patients with pulmonary capillaritis usually present with bilateral infiltrates on chest radiographs and can be acutely ill with diffuse alveolar hemorrhage that may be life threatening. Therapy depends on diagnosis of the underlying disease that gave rise to the capillaritis. Since many of the disorders leading to capillaritis are treated by immunosuppression with corticosteroids and cyclophosphamide or azathioprine, infection must be excluded early in the course of therapy.

Diagnosis of thyroid dysfunction: applied kinesiology compared to clinical observations and laboratory tests.

Sixty-five patients presenting to three clinics were independently evaluated for thyroid dysfunction by applied kinesiology (AK), a clinical protocol, and laboratory testing. Each was rated on a scale of 1 (unquestionably hypothyroid) to 7 (unquestionably hyperthyroid). AK ratings correlated with clinical ratings (rs = .36, p less than .002) and with laboratory ratings (rs = .32, p less than .005). Correlation between clinical and laboratory ratings was .47, p less than .000. Three AK therapy localizations had a significant correlation with the laboratory diagnosis (p less than .05). Two of these (right neurovascular-left brain and left neurolymphatic-right brain) were points associated with thyroid function. The third, ventral hand on the glabella with the other on the external occipital protuberance, is associated with pituitary function. AK enhanced but did not replace clinical/laboratory diagnosis of thyroid dysfunction. Preliminary evidence indicates that there may be a significant correlation between certain AK tests and an elevated LDH in the serum.

Genetic transformation of major wine grape cultivars of Vitis vinifera L.

We have developed an Agrobacterium-mediated transformation system for a number of important grapevine cultivars used in wine production. Transgenic plants were obtained for the seven cultivars: Cabernet Sauvignon, Shiraz, Chardonnay, Riesling, Sauvignon Blanc, Chenin Blanc and Muscat Gordo Blanco. Embryogenic callus was initiated from anther filaments and genotypic differences were observed for initiation and subsequent proliferation with Chardonnay responding most favourably to culture conditions. The transformation system allowed the recovery of germinating transgenic embryos 10-12 weeks after Agrobacterium inoculation and plants within 18 weeks. Examination of the expression patterns of the green fluorescent protein gene under the control of the CAMV35S promoter in leaf tissue of transgenic plants showed that for up to 35% of plants the pattern was not uniform. The successful transformation of a genetically diverse group of wine grape cultivars indicates that the transformation system may have general application to an even wider range of Vitis vinifera cultivars.

Reversed-phase high-performance liquid chromatographic assay for the determination of potency and impurities in tazadolene succinate bulk drug and capsules.

A reversed-phase assay based on high-performance liquid chromatography with a water-acetonitrile-tetrahydrofuran (THF)-triethylamine (TEA)-perchloric acid (pH 2.5) mobile phase and a Zorbax C8 column has been validated for the determination of the purity of tazadolene succinate (I) [E-(+/-)-1-(2-benzylidenecyclohexyl)azetidine succinate, U-53996H] bulk drug, the potency of tazadolene succinate hard-filled capsule formulations and impurity levels in bulk drug. The system resolves E- and Z-isomers and other structurally related molecules. Retention of these compounds is mainly dependent on the amount of acetonitrile and THF in the mobile phase. An amine must be present in the mobile phase to bring about elution of I. The potency assay utilizes testosterone as internal standard. Potency assays exhibited relative standard deviations (R.S.D.) of less than 1%. Quantitative recovery from hard-filled capsules (HFC) is obtained by using a simple extraction procedure. Potential process impurities, potential degradation products, and formulation excipients are resolved. The assay is linear for tazadolene succinate concentrations equivalent to 50-150% of the assay concentration. Impurities can be quantitated to levels equivalent to about 0.1% by weight with R.S.D. less than 5%. The estimated limit of detection for I is about 2 ng for a 20 microliters injection.

The molecular organisation of a B chromosome tandem repeat sequence from Brachycome dichromosomatica.

A high copy, tandemly repeated, sequence (Bd49) specific to the B chromosome and located near the centromere in Brachycome dichromosomatica was used to identify lambda genomic clones from DNA of a 3B plant. Only one clone of those analysed was composed entirely of a tandem array of the B-specific repeat unit. In other clones, the Bd49 repeats were linked to, or interspersed with, sequences that are repetitious and distributed elsewhere on the A and B chromosomes. One such repetitious flanking sequence has similarity to retrotransposon sequences and a second is similar to chloroplast DNA sequences. Of the four separate junctions analysed of Bd49-like sequence with flanking sequence, three were associated with the same A/T-rich region in Bd49 and the fourth was close to a 25 bp imperfect dyadic sequence. No novel B-specific sequences were detected within the genomic clones.

Thymohemangiolipoma, a rare histologic variant of thymolipoma: a case report and review of the literature.

We report a case of a thymic neoplasm in an 18-year-old woman who presented with chest discomfort and an anterior mediastinal mass. The surgically resected tumor showed abundant adipose tissue admixed with thymic tissue and numerous medium-caliber blood vessels. We consider this tumor a rare variant of thymolipoma and designate it as thymohemangiolipoma. Because of its benign nature, it should be distinguished from other mediastinal lesions.

From the archives of the AFIP: pulmonary vasculature: hypertension and infarction.

Pulmonary hypertension is the hemodynamic consequence of vascular changes within the precapillary (arterial) or postcapillary (venous) pulmonary circulation. These changes may be idiopathic, as in primary pulmonary hypertension or pulmonary veno-occlusive disease, but more commonly they represent a secondary response to alterations in pulmonary blood flow. The pulmonary and systemic bronchial circulations form broad anastomoses that largely prevent infarction except in settings of markedly elevated pulmonary venous pressure, underlying malignancy, or excessive embolic burden. Causes of precapillary pulmonary hypertension include long-standing cardiac left-to-right shunt, chronic thromboembolic disease, and widespread pulmonary embolism arising from intravascular malignant cells, parasites, or foreign materials. The classic radiologic features of precapillary pulmonary hypertension are central arterial enlargement, sharply pruned peripheral vascularity, and right-sided heart hypertrophy and chamber dilatation. Postcapillary pulmonary hypertension may develop secondary to focal venous constriction or to compromised pulmonary venous drainage due to left atrial neoplasia, mitral stenosis, or left ventricular failure. Radiologic manifestations of postcapillary pulmonary hypertension include prominent septal lines, small pleural effusions, and occasionally air-space opacities. In addition, radiologic evaluation of postcapillary pulmonary hypertension may demonstrate evidence of pulmonary arterial hypertension, secondary to the retrograde transmission of elevated pulmonary venous pressure across the capillary bed.

Organisation and origin of a B chromosome centromeric sequence from Brachycome dichromosomatica.

Brachycome dichromosomatica is an Australian native daisy that has two pairs of A chromosomes and up to three B chromosomes in some populations. A putative B-specific tandem repeat DNA sequence (Bd49) was isolated previously. Here we describe further characterisation of this sequence and investigate its possible origin. Southern analysis showed that all individual B chromosomes examined have highly methylated tandem repeats of Bd49 but differences in banding pattern for distinct B isolates suggested that the sequence is in a state of flux. Using in situ hybridisation, the sequence was shown to be located at the centromeric region of the B chromosome. Southern analysis of genomic DNA with Bd49 demonstrated that multiple copies of the sequence exist in the genomes of B. eriogona, B. ciliaris, B. segmentosa and B. multifida (none of which have B chromosomes) whereas other species tested (including 0B plants of B. dichromosomatica and 0B and +B B. curvicarpa and B. dentata) have few or no copies. Genomic clones and Bd49-like sequences derived by the polymerase chain reaction (PCR) were obtained from five species but determination of phylogenetic relationships within the genus and inference as to the possible origin of the B chromosome were problematic because of extensive intragenomic heterogeneity of the sequences.

Fibrosing mediastinitis.

Fibrosing mediastinitis is a rare benign disorder caused by proliferation of acellular collagen and fibrous tissue within the mediastinum. Although many cases are idiopathic, many (and perhaps most) cases in the United States are thought to be caused by an abnormal immunologic response to Histoplasma capsulatum infection. Affected patients are typically young and present with signs and symptoms of obstruction or compression of the superior vena cava, pulmonary veins or arteries, central airways, or esophagus. There may be two types of fibrosing mediastinitis: focal and diffuse. The focal type usually manifests on computed tomographic (CT) or magnetic resonance (MR) images as a localized, calcified mass in the paratracheal or subcarinal regions of the mediastinum or in the pulmonary hila. The diffuse type manifests on CT or MR images as a diffusely infiltrating, often noncalcified mass that affects multiple mediastinal compartments. CT and MR imaging play a vital role in the diagnosis and management of fibrosing mediastinitis.