Impact of outpatient SARS-CoV-2 infections in minority children

Data regarding COVID-19 in the adult population and hospitalized children is rapidly evolving, but little is known about children infected with severe acute respiratory syndrome coronavirus 2 who do not require hospitalization.In an observational, retrospective study we analyzed risk factors, demographics and clinical course of non-hospitalized patients ≤ 21 years of age with COVID-19 infection.Of the 1,796 patients evaluated, 170 were infected, and 40 participated in a telephone survey. Children older >10 years of age (OR: 2.19), Hispanic ethnicity (OR: 3) and residing in counties with higher rates of poverty (OR: 1.5) were associated with higher risk of infection, while older girls were more likely to experience prolonged duration of symptoms (median: 32 days). Consistent with prior reports, fever and cough were present in most of our patients. Shortness of breath, diarrhea, anosmia, and ageusia were more common in our outpatient population than previously reported.Larger studies addressing the clinical and psychosocial impact of CoVID-19 infection in children living in high-risk environments are warranted.

[Perampanel as a therapy option in patients with epilepsy]

BACKGROUND

This article describes a monocentric retrospective analysis of clinical experience with the latest antiepileptic drug perampanel with non-competitive modulation of postsynaptic AMPA receptors.

MATERIAL AND METHODS

Evaluation of electronic medical charts of patients newly treated with perampanel between 2012 and 2014 at the epilepsy center of the University Hospital Freiburg regarding effectiveness and tolerability.

RESULTS

A total of 85 patients (45 male, mean age 37.4 years, range 14-80 years) with therapy resistance to an average of 6 antiepileptic medications were newly treated with add-on perampanel. Of the patients 35 % experienced a relevant reduction in seizures. The most commonly reported side effects were tiredness (32.5 %), dizziness (24.5 %) and irritability (10.5 %). The dosages resulting in a significant reduction in seizures which varied between patients from 4 to 12 mg/day. Even multidrug-resistant patients who had not benefited from vagus nerve and deep brain stimulation, profited from add-on treatment with perampanel.

CONCLUSION

In this cohort, even epilepsy patients who did not respond to multiple previous antiepileptic treatment profited from add-on therapy with the new mode of action of perampanel.

Genetics and development of ocular oxidases in the mouse: evidence for a new locus (Eox-1) closely linked with the aldehyde oxidase loci on chromosome 1

Isoelectric focusing (IEF) and histochemical techniques were used to examine the genetics, postnatal development and biochemical properties of ocular oxidases (EOXs) among inbred strains of mice. The designation as EOX was made on a provisional basis, since the 'natural' substrate(s) for this enzyme have not been identified. Five major forms were resolved from adult animals, which exhibited high activity in murine lens and low activity in the cornea. An additional ocular oxidase was observed in neonatal animals. Genetic analyses demonstrated that one of these enzymes (EOX-1) is encoded by a locus (Eox-1) which is closely linked with, but distinct from, the aldehyde oxidase (Aox) gene complex on chromosome one of the mouse. These results support the proposal that ocular oxidases are distinct from the major liver AOXs in this organism.

Apoptosis in sulfur mustard treated A549 cell cultures

The chemical warfare agent sulfur mustard (SM) is a strong alkylating agent that leads to erythema and ulceration of the human skin several hours after exposure. Although SM has been intensively investigated, the cellular mechanisms leading to cell damage remain unclear. Apoptosis, necrosis and direct cell damage are discussed. In this study we investigated apoptotic cell death in pulmonary A549 cells exposed to SM (30-1000 microM, 30 min). 24 h after SM exposure DNA breaks were stained with the TUNEL method. Additionally, A549 cells were lysed and cellular protein was transferred to SDS page and blotted. Whole PARP as well as PARP cleavage into the p89 fragment, an indicator of apoptosis, were detected by specific antibodies. SM concentration dependent increase in TUNEL positive cells and PARP cleavage showed that SM is an inducer of apoptosis. It has been previously suggested that AChE is activated during apoptotic processes and may be involved in apoptosis regulation. Therefore, we examined AChE activity in A549 cells upon induction of apoptosis by SM (100-500 microM). Increased AChE activity was found in SM treated A549 cell cultures examined as determined by the Ellman's assay and by western blot. AChE activity showed a strong correlation with TUNEL positive cells. However, the broad caspase inhibitor zVAD and the PARP-inhibitor 3-aminobenzamide had no protective effect on A459 cells measured with AChE activity and frequency of TUNEL positive cells. In summary, our studies demonstrate that AChE activity may be a potential marker of apoptosis in A549 cells after SM injury. To what extent AChE is involved in apoptosis regulation during SM poisoning has to be further investigated.

[Isoprenoid pigments in representatives of the family Microbacteriaceae]

By using fosmidomycin and mevinolin (inhibitors of the synthesis of isoprenoid pigments), spectrophotometry, and mass spectrometry, the presence of isoprenoid pigments is shown in 71 of the 78 strains under study. All of these strains belong to 11 genera of the family Microbacteriaceae. Yellow, orange, and red pigments are found to have absorption spectra typical of C40-carotenoids. Eight out of the sixteen strains of the genus Microbacterium are able to synthesize neurosporene, a precursor of lycopene and beta-carotene. The biosynthesis of carotenoids in some representatives of the genera Agromyces, Leifsonia, and Microbacterium is induced by light. Inhibition of the biosynthesis of isoprenoid pigments by fosmidomycin suggests that they are synthesized via the nonmevalonate pathway. Twelve strains are found to exhibit both the nonmevalonate and mevalonate pathways of isoprenoid synthesis. These data, together with the difference in the inhibitory concentration of fosmidomycin, can be used for differentiating various taxa within the family Microbacteriaceae.

[Prevalence of nonmevalonate and mevalonate pathways for isoprenoid biosynthesis among bacteria of different systematic groups]

The effect of fosmidomycin and mevinoline, inhibitors of the nonmevalonate and the mevalonate pathway of isoprenoid biosynthesis, respectively, on the growth of 34 anaerobic and 10 aerobic prokaryotic strains was studied. Fosmidomycin at the concentrations used was shown to inhibit the growth of 9 (of 10) representatives of the family Microbacteriaceae, 4 (of 5) strains of Thermoanaerobacter, and 11 (of 12) strains of Clostridium, whereas mevinoline inhibited the growth of lactobacilli (Carnobacterium), methanogenic and sulfate-reducing bacteria insensitive to fosmidomycin. During the late growth phase, four strains of actinobacteria (of nine) accumulate the compound, which, upon oxidation, generates a long-lived free radical; three strains synthesize 2-C-methyl-D-erythritol-2,4-cyclopyrophosphate (MEC). It was concluded that the difference in the sensitivity of the organisms to fosmidomycin and mevinoline might serve as a test to differentiate several representatives of the family Microbacteriaceae. The use of mevinoline for inhibiting methanogens in ecological investigations seems to be promising.

Identification of (E)-4-hydroxy-3-methyl-but-2-enyl pyrophosphate as a major activator for human gammadelta T cells in Escherichia coli

The gcpE and lytB gene products control the terminal steps of isoprenoid biosynthesis via the 2-C-methyl-D-erythritol 4-phosphate pathway in Escherichia coli. In lytB-deficient mutants, a highly immunogenic compound accumulates significantly, compared to wild-type E. coli, but is apparently absent in gcpE-deficient mutants. Here, this compound was purified from E. coli DeltalytB mutants by preparative anion exchange chromatography, and identified by mass spectrometry, (1)H, (13)C and (31)P NMR spectroscopy, and NOESY analysis as (E)-4-hydroxy-3-methyl-but-2-enyl pyrophosphate (HMB-PP). HMB-PP is 10(4) times more potent in activating human Vgamma9/Vdelta2 T cells than isopentenyl pyrophosphate.

LytB, a novel gene of the 2-C-methyl-D-erythritol 4-phosphate pathway of isoprenoid biosynthesis in Escherichia coli

The mevalonate-independent 2-C-methyl-D-erythritol 4-phosphate (MEP) pathway for isoprenoid biosynthesis is essential in many eubacteria, plants, and the malaria parasite. Using genetically engineered Escherichia coli cells able to utilize exogenously provided mevalonate for isoprenoid biosynthesis by the mevalonate pathway we demonstrate that the lytB gene is involved in the trunk line of the MEP pathway. Cells deleted for the essential lytB gene were viable only if the medium was supplemented with mevalonate or the cells were complemented with an episomal copy of lytB.

GcpE is involved in the 2-C-methyl-D-erythritol 4-phosphate pathway of isoprenoid biosynthesis in Escherichia coli

In a variety of organisms, including plants and several eubacteria, isoprenoids are synthesized by the mevalonate-independent 2-C-methyl-D-erythritol 4-phosphate (MEP) pathway. Although different enzymes of this pathway have been described, the terminal biosynthetic steps of the MEP pathway have not been fully elucidated. In this work, we demonstrate that the gcpE gene of Escherichia coli is involved in this pathway. E. coli cells were genetically engineered to utilize exogenously provided mevalonate for isoprenoid biosynthesis by the mevalonate pathway. These cells were then deleted for the essential gcpE gene and were viable only if the medium was supplemented with mevalonate or the cells were complemented with an episomal copy of gcpE.

A family of secreted mucins from the parasitic nematode Toxocara canis bears diverse mucin domains but shares similar flanking six-cysteine repeat motifs

Infective larvae of the parasitic nematode Toxocara canis secrete a family of mucin-like glycoproteins, which are implicated in parasite immune evasion. Analysis of T. canis expressed sequence tags identified a family of four mRNAs encoding distinct apomucins (Tc-muc-1-4), one of which had been previously identified in the TES-120 family of glycoproteins secreted by this parasite. The protein products of all four cDNAs contain signal peptides, a repetitive serine/threonine-rich tract, and varying numbers of 36-amino acid six-cysteine (SXC) domains. SXC domains are found in many nematode proteins and show similarity to cnidarian (sea anemone) toxins. Antibodies to the SXC domains of Tc-MUC-1 and Tc-MUC-3 recognize differently migrating members of TES-120. TES-120 proteins separated by chromatographic methods showed distinct amino acid composition, mass, and sequence information by both Edman degradation and matrix-assisted laser desorption ionization/time of flight mass spectrometry on peptide fragments. Tc-MUC-1, -2, and -3 were shown to be secreted mucins with real masses of 39.7, 47.8, and 45.0 kDa in contrast to their predicted peptide masses of 15.7, 16.2, and 26.0 kDa, respectively. The presence of SXC domains in all mucin products supports the suggestion that the SXC motif is required for mucin assembly or export. Homology modeling indicates that the six-cysteine domains of the T. canis mucins adopt a similar fold to the sea anemone potassium channel-blocking toxin BgK, forming three disulfide bonds within each subunit.

Identification of a new C-type lectin, TES-70, secreted by infective larvae of Toxocara canis, which binds to host ligands

Infective larvae of the dog roundworm Toxocara canis survive in the tissues of their hosts for extended periods in a state of developmental arrest, successfully evading immune destruction. This survival strategy is thought to be mediated by T. canis excretory/secretory (TES) products which downregulate or divert the immune response. We purified one of the major TES products, TES-70 and gained amino acid sequence from 4 tryptic peptides. These peptides were matched to a predicted protein from a cDNA that was isolated by expression screening a T. canis cDNA library with mouse anti-TES serum. The predicted protein (Tc-CTL-4) is similar to, but larger than, Tc-CTL-1, a 32-kDa C-type lectin secreted by T. canis larvae. Tc-CTL-4 has a signal peptide, 2 Cys-rich domains and a C-terminal calcium-dependent C-type lectin domain that shares sequence similarity with host immune cell receptors such as macrophage mannose receptor and CD23. The lectin domain was expressed in bacteria and antiserum to the purified recombinant protein was used to confirm that Tc-ctl-4 did encode the native TES-70 glycoprotein. TES-70 selectively bound to ligands on the surface of Madin-Darby Canine Kidney cells in vitro in a calcium-dependent manner, inhibitable by mammalian serum, indicating that a host glycan is the native ligand for this new parasite lectin.

Tools for discovery of inhibitors of the 1-deoxy-D-xylulose 5-phosphate (DXP) synthase and DXP reductoisomerase: an approach with enzymes from the pathogenic bacterium Pseudomonas aeruginosa

Two Pseudomonas aeruginosa genes encoding the enzymes 1-deoxy-D-xylulose 5-phosphate (DXP) synthase and DXP reductoisomerase, both involved in the mevalonate-independent biosynthesis of isoprenoids, have been expressed as recombinant enzymes in Escherichia coli. The purified P. aeruginosa DXP reductoisomerase was inhibited by submicromolar concentrations of the antibiotics fosmidomycin and FR-900098 in a well established method. A novel and convenient spectrophotometric assay was developed to determine activity and inhibition of P. aeruginosa DXP synthase. Fluoropyruvate is described as a first inhibitor of DXP synthase.

Recombinant expression and modification analysis of protein agno-1b encoded by avian polyomavirus BFDV

Among two pairs of agnoproteins encoded in upstream positions in the late mRNAs of avian polyomavirus BFDV, either agno-1a or its splice derivative agno-1b are required for viral propagation. Out of the two proteins both of which consist of multiple electrophoretic subspecies, the smaller and less complex agno-1b has been cDNA-cloned into an influenza-virus /RNA-polymerase I expression system for production of higher amounts of this protein in infected chicken embryo fibroblasts. Fractional modification of agno-1b by phosphorylation at residues serine 51, serine 53, and threonine 73 is demonstrated through dephosphorylation by alkaline phosphatase, mass spectrometry of individual protein species isolated by strong anion exchange chromatography, and single or multiple alanine substitutions of serine or threonine residues in site-directed mutagenesis.

Inhibitors of the nonmevalonate pathway of isoprenoid biosynthesis as antimalarial drugs

A mevalonate-independent pathway of isoprenoid biosynthesis present in Plasmodium falciparum was shown to represent an effective target for chemotherapy of malaria. This pathway includes 1-deoxy-D-xylulose 5-phosphate (DOXP) as a key metabolite. The presence of two genes encoding the enzymes DOXP synthase and DOXP reductoisomerase suggests that isoprenoid biosynthesis in P. falciparum depends on the DOXP pathway. This pathway is probably located in the apicoplast. The recombinant P. falciparum DOXP reductoisomerase was inhibited by fosmidomycin and its derivative, FR-900098. Both drugs suppressed the in vitro growth of multidrug-resistant P. falciparum strains. After therapy with these drugs, mice infected with the rodent malaria parasite P. vinckei were cured.

Juvenile female Litomosoides sigmodontis produce an excretory/secretory antigen (Juv-p120) highly modified with dimethylaminoethanol

A 120 kDa antigen produced by juvenile female Litomosoides sigmodontis (Juv-p120) was isolated and purified. The amino acid composition of the molecule was determined. Juv-p120 was shown to be highly modified with N,N-dimethyl-aminoethanol (28.4 mol%). Treatment of Juv-p120 with potassium hydroxide (beta-elimination) or with sodium m-periodate leads to the destruction of epitopes recognized by antibodies immune affinity-purified with isolated Juv-p120. Juvenile L. sigmodontis were shown to release Juv-p120 into the pleural cavity of infected Mastomys coucha before the onset of patency.

Localization of the palmitoylation site in the transmembrane protein p12E of Friend murine leukaemia virus

Friend murine leukaemia virus complex was propagated on murine cells in the presence of [9,10-3H]palmitic acid. Virus particles were harvested from the culture supernatant and lysed with detergents. The viral transmembrane protein, p12E, was isolated from the lysates by size-exclusion chromatography and purified by narrowbore reverse-phase HPLC. Analysis of the purified product by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS) revealed that the protein is palmitoylated carrying one fatty acid residue. The radiolabelled fatty acid was released by hydroxylamine treatment at pH 7, indicating that acylation occurred via a thioester linkage. For allocation of the acylation site, p12E was digested with trypsin. The resulting peptides were either directly subjected to MALDI-TOF-MS or fractionated by microbore reverse-phase HPLC prior to mass spectrometry. The results revealed that p12E of Friend murine leukaemia virus is acylated at a cysteine residue situated at the C-terminal side of the putative transmembrane anchor of the polypeptide. Fatty acid analysis of the purified acylpeptide demonstrated that p12E carries almost exclusively palmitic acid.

Brugia spp. and Litomosoides carinii: identification of a covalently cross-linked microfilarial sheath matrix protein (shp2)

A microfilarial sheath protein gene (shp2) coding for the major constituent of the insoluble, cross-linked sheath remnant (SR) from Brugia malayi, Brugia pahangi and Litomosoides carinii has been cloned and sequenced, based on peptide partial amino-acid sequences. All three closely related single-copy shp2 genes in the two genera carry a single intron in identical position; shp2 mRNAs are post-transcriptionally modified by both cis-splicing and trans-splicing. In accordance with their extracellular destinations the encoded proteins include signal peptide sequences; molecular masses of approx. 23 kDa are hence predicted for the mature secreted polypeptides. In their structures sheath matrix proteins shp2 may be regarded as extreme cases of a modular constitution, since these proteins largely consist of two different segments of multiple sequence repetitions, PAA and QYPQAP (or QYPQ), separated by elements of unique sequence. Extreme insolubility and cross-linking are likely to originate from these repetitive sequences within shp2, and to constitute the basic properties of a microfilarial matrix largely consisting of an shp2 network.

Litomosoides carinii microfilarial sheaths: partial amino acid sequences of several major polypeptide constituents

Isolated sheaths from Litomosoides carinii microfilariae were disintegrated by reduction with dithiothreitol and were 14C-carboxymethylated. Five major sheath proteins thus solubilized were purified by size exclusion chromatography and reversed-phase HPLC (rpHPLC). Proteolytic fragments of complete sheaths and of the single sheath proteins were isolated by rpHPLC and were N-terminally sequenced. A library of 27 partial sheath polypeptide sequences was thus established, 21 of which could be assigned to three L. carinii sheath structural genes (shp1,2, and 3/3a) isolated on the basis of this and of previous amino acid sequence information. The remaining peptides document the presence of at least one additional major sheath constituent.

Increased copy number at 20q13 in breast cancer: defining the critical region and exclusion of candidate genes

Studies by comparative genomic hybridization have indicated that a major new locus for DNA amplification in breast cancer is 20q13 and suggested that this genetic event is associated with aggressive clinical behavior. We used interphase fluorescence in situ hybridization with anonymous cosmid probes and gene-specific P1 clones to determine the minimal common region of increased copy number and to study involvement of known genes at 20q13. Based on high-level copy number increases (3 to 10-fold) found with one or more probes in 5 of 14 (35%) breast cancer cell lines and in 3 of 36 (8%) primary tumors, the critical region was narrowed to approximately 1.5 megabases at 20q13.2 defined by fractional length pter values 0.81-0.84. Previously known genes were excluded as candidates, implying that this chromosomal region harbors a novel oncogene that contributes to the malignant progression of breast cancer.

Litomosoides carinii: extraction of the microfilarial sheath components and antigenicity of the sheath fractions

Microfilarial sheaths of Litomosoides carinii were isolated and extracted with 2% sodium dodecyl sulfate (SDS) and 5% 2-mercaptoethanol (2ME). Extraction with SDS alone did not alter the ultrastructure of the sheaths and yielded five polypeptides (27-67 kDa) that were not recognized by antibodies of infected hosts but reacted with antibodies to host-serum proteins. 2ME treatment caused partial solubilization of the sheaths (45% as determined by amino acid analysis), which could be further improved by combining 2ME with SDS. The remainder showed filamentous/threadlike structures on electron microscopic examination. As compared with whole sheaths, the insoluble proportion was markedly enriched in alanine and cysteine but contained less galactosamine, serine, and threonine. SDS-polyacrylamide gel electrophoresis (SDS-PAGE) of 2ME/SDS-extractable components showed 12-16 bands of 14- greater than 120 kDa. A predominant component had an apparent molecular mass of 22 kDa. Two bands (42 and 120 kDa) could be stained with Coomassie blue but showed "negative" staining when gels were stained with silver. Several components (but not the 22-kDa polypeptide) bore phosphocholine epitopes. Apart from the negatively staining bands, most of the 2ME-soluble sheath components were recognized by antibodies of L. carinii-infected Mastomys coucha. Except for several polypeptides that had been unspecifically recognized by IgM, the antibody response to sheath components started at the end of the prepatent period.

A major Litomosoides carinii microfilarial sheath glycoprotein (gp22): amino terminal sequence and immunological studies with corresponding synthetic peptides

The major glycoprotein of the sheath of Litomosoides carinii microfilariae (gp22) was analysed for its amino acid and amino sugar composition. It is rich in proline, glutamine/glutamic acid and glycine and contains (N-acetyl)galactosamine. The N-terminal amino acid sequence was determined up to position 37. It consists of a group of 6 repeats of the pentapeptide sequence methionine-glycine-proline-glutamine-proline with two minor modifications in repeats 3-6, while the first two repeats follow the general pattern more loosely. Identical N-terminal amino acid sequences were found in at least two other sheath polypeptides (33 kDa, 39 kDa). Antisera prepared against 3 overlapping synthetic peptides corresponding to the amino terminus of gp22 recognized different epitopes. They all reacted with identical patterns of sheath polypeptides. The antisera failed to recognize antigens of 4th-stage larvae of L. carinii. In contrast, cross-reacting epitopes were detected in other parasite stages. Antisera reacted with material surrounding embryos and microfilariae in the uterus of females, and caused patchy fluorescence on the sheath of blood-derived and in vitro-released microfilariae.

Purification to homogeneity of pyrroline-5-carboxylate reductase of barley

An enzyme has been purified to homogeneity from barley seedlings which has ;proline dehydrogenase' and the pyrroline-5-carboxylic acid reductase activities. The purification achieved is 39,000-fold as calculated from the proline dehydrogenase activity. The subunit molecular weight of the protein is 30 kilodaltons. The native enzyme has molecular weights up to 480 kilodaltons, depending on the buffer environment. From the pH profiles, the specific activities and thermodynamic considerations, it is concluded that the plant proline dehydrogenase functions in vivo as a pyrroline-5-carboxylate reductase.

Sensitive radioimmunoassay for the broad-spectrum antiviral agent ribavirin

Ribavirin, 1-beta-D-ribofuranosyl-1,2,4-triazole-3-carboxyamide (Virazole; Viratek, Inc., Covina, Calif.), has a broad spectrum of antiviral activity. However, the study of the absorption, metabolism, and excretion of this compound has been limited by the lack of an appropriate assay for ribavirin and its metabolites. Since ribavirin has definite potential for therapeutic use, we developed a radioimmunoassay to measure ribavirin levels in clinical specimens. To prepare an effective immunogen, ribavirin was monosuccinylated and coupled to ovalbumin. The competitive binding radioimmunoassay, in which tritium-labeled ribavirin and rabbit antiribavirin serum were used, was quantitative for ribavirin at concentrations of 1 pmol/100 microliter in urine or plasma samples. The rabbit antibody cross-reacted with the major metabolite of ribavirin, 1,2,4-triazole-3-carboxamide, at a low level (2 to 5%) which did not interfere with ribavirin binding until concentrations of 1,2,4-triazole-3-carboxamide 10- to 100-fold higher than ribavirin were present in mock samples, a condition not present in biological specimens. We used the ribavirin radioimmunoassay to determine the ribavirin concentration in mouse plasma after intraperitoneal administration, in the sera of adults from Sierra Leone after oral or intravenous administration for treatment of suspected Lassa fever, and in the sera of children in the United States after small-particle aerosol administration. Our experience with the radioimmunoassay indicates that it is sensitive, accurate, and reproducible. The assay will permit studies leading to a better understanding of the pharmacology and pharmacokinetics of this potentially useful antiviral drug.

Treatment of cytomegalovirus pneumonia with high-dose acyclovir

Cytomegalovirus pneumonia is a serious complication of marrow transplantation, with a 90 percent fatality rate. Acyclovir, a new antiviral agent with variable in vitro activity against cytomegalovirus, was administered to eight marrow transplant patients with biopsy-proven cytomegalovirus pneumonia; one patient survived. Doses were between 400 and 1200 mg/m2 and peak plasma levels between 47 and 316 microM were attained. Possible marrow toxicity occurred in three patients, and mild neurotoxicity occurred in one. High-dose acyclovir had mild toxicity but was not effective as treatment for cytomegalovirus pneumonia after marrow transplantation.

Neonatal acyclovir pharmacokinetics in patients with herpes virus infections

A preliminary analysis is presented of the pharmacokinetics of acyclovir in neonatal patients with herpes simplex virus infections. Mean peak acyclovir levels (microM +/- SD) at 5, 10, and 15 mg/kg per dose were 30.0 +/- 9.9, 61.2 +/- 18.3, and 86.1 +/- 23.5, with corresponding mean trough levels (microM +/- SD) of 5.3 +/- 3.4, 10.1 +/- 8.4, and 13.8 +/- 11.1, respectively. The mean half-life (t 1/2 beta) of acyclovir was 3.78 +/- 1.21 hours. The mean percent urinary recovery of acyclovir (+/- SD) at each dosage level was similar, with an overall mean recovery of 65 percent. The mean acyclovir concentration in urine did not exceed the solubility of acyclovir in bladder urine (1,300 micrograms/ml). Generally, neonatal acyclovir pharmacokinetics was consistent with previous reports from studies of adults.

Pharmacokinetics of orally administered acyclovir in patients with herpes progenitalis

The pharmacokinetics of acyclovir administrated orally in a dose of 200 mg every four hours, five times a day to adults with herpes progenitalis was determined. Peak plasma acyclovir levels are found 1.5 to 1.75 hours after oral administration; peak levels range from 1.4 to 4.0 microM with a mean of 2.5 microM. Acyclovir levels in saliva are well correlated with simultaneous plasma levels, saliva levels being approximately 13 percent of plasma levels. Simultaneous plasma and vaginal secretion acyclovir levels are poorly correlated; peak levels in vaginal secretions range from 0.5 to 3.6 microM.

Treatment of herpes virus infections in immunocompromised patients with acyclovir by continuous intravenous infusion

Sixteen immunocompromised patients with herpes virus infections were treated for three to five days with continuously administered intravenous acyclovir. Patients received initial acyclovir infusions over 5 minutes in dosages ranging from 1.5 to 5.0 mg/kg followed by continuously infused acyclovir at 7.2, 14.4, 21.6, 28.8, 36.0, or 43.2 mg/kg per day. The mean serum plateau levels of acyclovir determined by radioimmunoassay ranged from 4.1 microM for the 7.2 mg/kg per day dosage to 36.6 microM for the 43.2 mg/kg per day dose. A mean of 75 percent of acyclovir administered was recovered in the urine of patients treated. Eleven of 13 patients with varicella-zoster virus (VZV) infections had no new vesicle formation after three days of acyclovir treatment and all patients ceased to have new vesicles after five days of therapy. For the nine patients from whom complete viral cultures were available, six ceased to shed virus at three days, and viral shedding ceased by five days in all patients treated with acyclovir. No clinical or laboratory adverse reactions were associated with acyclovir therapy. These data suggest that acyclovir given by continuous intravenous infusion may be useful in the treatment of herpes virus infections in immunocompromised patients.

Single-dose pharmacokinetics of acyclovir

The pharmacokinetics of intravenously administered acyclovir were studied in 10 patients with advanced malignancies. After doses of 0.5 and 1.0 mg/kg, the slow disposition half-life values (t1/2beta) ranged from 2.2 to 3.1 h for the 1-h infusions and from 1.8 to 3.7 h for the 6-h infusions. Plasma levels, measured by radioimmunoassay, reached a maximum at the end of the 1-h infusions and approached steady state at 3 to 4 h into the 6-h infusions. Mean peak plasma concentrations obtained at 0.5 and 1.0 mg/kg administered over 1 h were 3.03 and 5.99 microM, respectively. Mean peak levels for the 6-h infusions were 1.07 microM at 0.5 mg/kg and 2.58 microM at 1.0 mg/kg. The mean urinary elimination of acyclovir was 44.7% of the administered doses. No clinical or laboratory abnormalities were noted in the 10 patients studied.

Analyses of stage-specific multiple forms of lactate dehydrogenase and of cytochrome c during spermatogenesis in the mouse

Spermatogenesis is a programmed developmental process characterized by the inactivation of certain genes and the activation of other, testis-specific genes. Synthesis of unique gene products such as LDH-C4 and cytochrome ct occurs only at precise stage of germ cell formation. The developmental sequences of gene activation for these proteins was observed by immunohistochemical procedures. LDH-C4 is first detectable during mid-pachytene of the primary spermatocyte. The C subunits appear to be uniformly distributed throughout the cytoplasm of the spermatocyte. The mid-pachytene stage also marks the first appearance of cytochrome ct. The association of this electron transport protein with spermatocyte mitochondria is reflected in a granular fluorescence of specific antibody-treated sections of testis. Neither the C subunit of LDH, nor cytochrome ct appear in leptotene or early pachytene primary spermatocytes. These analyses indicate that there is stage-specific protein synthesis in the primary spermatocyte which is characterized by differential activation of the LDH-C locus and of the gene coding for cytochrome ct.