Oxazolidinones, a new class of synthetic antibacterial agents: in vitro and in vivo activities of DuP 105 and DuP 721

DuP 721 (p-acetylphenyloxooxazolidinylmethylacetamide) and DuP 105 (a methylsulfinyl derivative) are orally active representatives of the oxazolidinones, a new class of synthetic antibacterial agents. Their antibacterial spectrum includes staphylococci, streptococci, and Bacteroides fragilis strains. The compounds have equal activity against staphylococcal strains susceptible or resistant to beta-lactam antibiotics, including methicillin-resistant strains. The MICs for 90% of the strains (MIC90s) against staphylococcal isolates were 1 to 4 micrograms/ml for DuP 721 and 4 to 16 micrograms/ml for DuP 105, compared with 1 to 2 micrograms/ml for vancomycin, 0.5 microgram/ml for ciprofloxacin, and 2 to greater than 16 micrograms/ml for imipenem. The MIC90s against group D streptococci were 4 micrograms/ml for DuP 721, 16 micrograms/ml for DuP 105, and 2 micrograms/ml for vancomycin, ciprofloxacin, and imipenem. MIC90s against B. fragilis isolates were 4 micrograms/ml for DuP 721, 16 micrograms/ml for DuP 105, and 8 micrograms/ml for cefoxitin. DuP 721 and DuP 105 administered by either the oral or the parenteral route were protective against staphylococcal and streptococcal infections in mice. The 50% effective doses were 2 to 10 mg/kg for DuP 721, 9 to 23 mg/kg for DuP 105, and 2 to 12 mg/kg for vancomycin. These results indicate that further studies of compounds of the oxazolidinone series are warranted.

Antibacterials. Synthesis and structure-activity studies of 3-aryl-2-oxooxazolidines. 1. The "B" group

The synthesis and structure/activity studies of the effect of varying the "B" group in a series of oxazolidinone antibacterials (I) are described. Two synthetic routes were used: (1) alkylation of aniline with glycidol followed by dialkyl carbonate heterocyclization to afford I (A = H, B = OH), whose arene ring was further elaborated by using electrophilic aromatic substitution methodology; (2) cycloaddition of substituted aryl isocyanates with epoxides to give A and B with a variety of values. I with B = OH or Br were converted to other "B" functionalities by using SN2 methodology. Antibacterial evaluation of compounds I with A = acetyl, isopropyl, methylthio, methylsulfinyl, methylsulfonyl, and sulfonamido and a variety of different "B" groups against Staphylococcus aureus and Enterococcus faecalis concluded that the compounds with B = aminoacyl, and particularly acetamido, were the most active of those examined in each A series, possessing MICs in the range of 0.5-4 micrograms/mL for the most active compounds described.

Haemoglobin gene frequencies in the Jamaican population: a study in 100,000 newborns

The gene frequencies of abnormal haemoglobins have been determined in a group of 100,000 Jamaican newborns screened over a period of 8 1/2 years. The population is predominantly of West African origin and the survey represents approximately one quarter of all island deliveries within the period of the study. The common beta globin chain abnormalities beta s and beta c occurred with gene frequencies of 0.055 and 0.019 respectively; beta thalassaemia was relatively rare. In contrast, alpha thalassaemia was quite common, occurring with a gene frequency of 0.183. In addition to these common abnormalities, the frequencies of 256 rare abnormal haemoglobins are described. This survey thus represents a complete and accurate documentation of the alpha and beta globin variants that occur in the Jamaican population.

Immunofluorescence on split skin for the detection and differentiation of basement membrane zone autoantibodies

The autoimmune subepidermal bullous diseases are characterized by autoantibodies to the basement membrane zone of stratified squamous epithelium. Recent studies have shown that the antibodies have characteristic ultrastructural and antigenic binding properties and that differentiating between those properties can be useful in distinguishing one disease from another. Immunofluorescence microscopy is widely used to detect basement membrane zone autoantibodies. The test has traditionally used tissue substrates with an intact basement membrane zone. Those substrates are limited because autoantibody binding cannot always be detected and because autoantibodies with different ultrastructural and antigenic binding properties cannot be distinguished from each other. Normal human skin that has been separated through the basement membrane zone (i.e., split skin) has recently been used as a substrate for detecting and characterizing basement membrane zone autoantibodies by immunofluorescence. Studies indicate that split skin is a more sensitive substrate than intact skin for detecting the antibodies and that antibodies with different ultrastructural binding sites can often be differentiated from one another on split skin. Those studies suggest split skin is the substrate of choice for the routine immunofluorescence evaluation of autoimmune subepidermal bullous diseases.

Antibacterials. synthesis and structure-activity studies of 3-aryl-2-oxooxazolidines. 4. Multiply-substituted aryl derivatives

The synthesis and structure-activity relationship (SAR) studies of the effect of different polysubstitution patterns in the aromatic ring of 5-(acetamidomethyl)oxazolidinone antibacterials (I) on antibacterial activity are presented. Compounds I were prepared by the six-step synthesis described previously (Gregory, W. A.; et al. J. Med. Chem. [formula: see text] 1989, 32, 1673), electrophilic aromatic substitution reactions of 3-substituted compounds, and functional-group interchange reactions of 3,4-disubstituted compounds. Antibacterial evaluation of compounds I against Staphylococcus aureus and Enterococcus faecalis gave the following results. The 2,4- and 2,5-disubstituted derivatives have weak or no antibacterial activity. Antibacterial activities of 3,4-disubstituted compounds are comparable to those of the 4-monosubstituted analogues for small 3-substituents (smaller than Br), but decline rapidly for larger 3-substituents. 3,4-Annulated derivatives are comparable in activity to their open-chain analogues. 3,5-Disubstituted and 3,4,5- and 2,4,6-trisubstituted derivatives are devoid of antibacterial activity.

Best practices for managing surgical services: the role of coordination

Growing evidence exists that patient outcomes are related to how effectively health care organizations coordinate work responsibilities among their staffs. However, information is lacking on actual practices that can be used to achieve effective coordination. This article reports on a National Veterans Affairs Surgical Risk Study, in which the authors studied the coordination practices of 20 surgical services that, based on risk-adjusted mortality and morbidity rates, occupied different ends of the patient outcomes continuum.

Congenital ectropion uveae with glaucoma

Congenital ectropion uveae (CEU) is a rare, nonprogressive anomaly characterized by the presence of iris pigment epithelium on the anterior surface of the iris stroma, often associated with neurofibromatosis and occasionally with other ocular anomalies. We present eight patients with unilateral CEU. Seven patients had glaucoma in the involved eye, while the eighth was a 10-week-old infant. In the two patients with bilateral glaucoma, the second eye was similar to the first, but without CEU. Three patients had neurofibromatosis, two had facial hemihypertrophy, one had Rieger's anomaly, one had Prader-Willi syndrome, and one had no systemic anomalies. Two had initially been misdiagnosed as having a large pupil in the involved eye and one as having a Horner's syndrome in the uninvolved eye. The finding of CEU in an infant warrants continued observation for the development of glaucoma and disorders of neural crest origin.

In vitro and in vivo antibacterial effects of combinations of beta-lactam antibiotics

The effects of combining the new broad-spectrum penicillins piperacillin and mezlocillin with cefoxitin, cefamandole, or cephalothin on the antibacterial activities of these antibodies were determined in vitro against 50 to 109 bacterial strains and in six experimental infections in mice. Against strains of Escherichia coli, Klebsiella, Proteus mirabilis, Salmonella, Acinetobacter, Enterococcus, and Staphylococcus, the combinations exhibited synergistic, indifferent, or additive effects, but no antagonism. Against strains of four groups of organisms (Pseudomonas, Serratia, Enterobacter, and indole-positive Proteus), a high incidence of antagonism was observed, particularly with combinations containing cefoxitin (60 to 100%). The penicillins were antagonized by the cephalosporin antibiotics. In vitro effects were reflected in vivo. Mice infected with cultures associated with synergistic or additive in vitro effects were protected with lower doses of piperacillin when this antibiotic was administered with ineffective doses of cefoxitin than when piperacillin was used alone. Infections with cultures associated with in vitro antagonism required two- to eightfold higher doses of piperacillin and mezlocillin when these antibiotics were used in combination with the cephalosporins. The clinical implications of these effects should be considered.

Newborn sickle cell disease screening: the Jamaican experience (1995–2006)

Objectives: The aim of this study was to evaluate the existing newborn sickle haemoglobinopathy screening programme in Jamaica.

Methods: A retrospective analysis of infants screened during the period 8 November 1995 to 22 July 2006 was performed. Patient data for analyses was restricted to patients with homozygous (Hb SS) sickle cell disease. Published data from the Jamaican Sickle Cell Cohort Study was used to make comparisons with the study sample.

Results: The study sample consisted of 435 patients with Hb SS disease. Acute chest syndrome was the most common clinical (non-death) event accounting for ∼50% of all events. Acute splenic sequestration, no longer a significant cause of mortality, was responsible for ∼32% of clinical events. Seven deaths (1.8%) occurred during the study period compared with 17.6% to the same age in the Jamaican Sickle Cell Cohort Study. There was a lower proportion of hospital admissions and episodes of serious illness in the study group compared with controls.

Conclusions: Survival estimates for the study sample showed improvement compared with the Jamaican Sickle Cell Cohort Study. This study continues to demonstrate the benefits of, and as such shows support for, newborn screening and early interventions in sickle cell disease. In addition, it highlights some of the areas for continued focus and research development. Although the current system is providing an essential and beneficial service, the study emphasizes the need for newborn screening programmes to be comprehensive care systems to be fully effective.

Structure-activity relationship of quinoline carboxylic acids. A new class of inhibitors of dihydroorotate dehydrogenase

The novel anticancer drug candidate brequinar sodium [DuP 785, NSC 368390, 6-fluoro-2-(2'-fluoro-1,1'-biphenyl-4-yl)-3-methyl-4-quinoline carboxylic acid sodium salt] inhibits dihydroorotate dehydrogenase, the fourth enzyme in the de novo pyrimidine biosynthetic pathway leading to the formation of UMP. Sixty-nine quinoline 4-carboxylic acid analogs were analyzed as inhibitors of L1210 dihydroorotate dehydrogenase. This structure-activity relationship study identified three critical regions of brequinar sodium and its analogs, where specific substitutions are required for the inhibition of the activity of dihydroorotate dehydrogenase. The three principal regions are: (i) the C(2) position where bulky hydrophobic substituents are necessary, (ii) the C(4) position which has a strict requirement for the carboxylic acid and its corresponding salts, and (iii) the benzo portion of the quinoline ring with appropriate substitutions. These results will be useful in the elucidation of the precise nature of the interaction between brequinar sodium and dihydroorotate dehydrogenase.

Retinal detachment and miotic therapy

We studied a series of 34 eyes in 31 patients in whom retinal detachment occurred during miotic therapy. In 14 eyes, the duration of miotic use before the development of detachment was two months or less. Most detachments occurred in detachment-prone eyes either by virtue of myopia (62%), aphakia (24%), ipsilateral lattice degeneration (38%) or retinal pathology, in the fellow eye (50%). Virtually all detachments were rhegmatogenous. Distributions of retinal breaks are similar to the corresponding profiles in detached eyes not receiving miotics. The observed phenomena may be accounted for mechanistically, either with or without the role of miotics, so a specific causal role cannot be assigned to any given miotic in any given case. However, our data suggest that detachment-prone eyes may be at increased risk with miotic use, and thus demand careful retinal evaluation and prophylaxis when ominous peripheral symptoms are present.

Adrenocortical atrophy and diffuse cerebral sclerosis

A boy, diagnosed as having Addison's disease due to idiopathic atrophy of the adrenal glands at the age of 7 years, developed the first evidence of what was originally thought to be `Schilder's disease' at 8 years and 10 months. He died at 9 years and 11 months. There was a very striking family history of autoimmune disorders on the mother's side. The clinical and pathological aspects of his case are outlined. Detailed studies of adrenal function during life showed a diminution in excretion of adrenal androgens and corticosteroids before therapy which was not evident from the 17-oxosteroid and 17-hydroxycorticosteroid assays in the resting state, though the initial diagnosis was based on the failure of ACTH to produce a rise in the 17-hydroxycorticosteroid excretion. No unusual or abnormal steroids were detected nor was there any disproportion between the androgen and corticosteroid excretion to suggest an adrenal enzyme deficiency. The biochemistry of the brain at necropsy revealed the changes expected in a demyelinating disorder, but the detection of abnormalities in the grey matter distinguished the condition from `Schilder's disease' in which the biochemistry of the grey matter is normal. There are 12 fully documented reports of boys with adrenocortical atrophy and diffuse cerebral sclerosis, and it is thought that this rare entity is inherited as an X-linked recessive characteristic. The two likely theories of causation involve either an error of metabolism common to the adrenal cortex and the brain, or the possibility that both the adrenal and brain pathology are due to an autoimmune disorder.

Efficacy of 1-beta-D-ribofuranosyl-1,2,4-triazole-3-carboxamide against influenza virus infections in mice

1-beta-d-Ribofuranosyl-1,2,4-triazole-3-carboxamide (ribavirin) was effective against strains of influenza virus types A and F, whereas amantadine hydrochloride was effective only against strains of influenza virus type A. Dose-related protective effects against lethal influenza infections in mice were obtained with single oral doses of 25 to 400 mg of ribavirin per kg administered at the time of virus inoculation or up to 24 h thereafter. Therapeutic indexes (maximum tolerated dose/median effective dose) against various strains of influenza virus ranged from 5 to 35. With multiple-dose treatment initiated immediately after virus inoculation, oral doses as low as 12 to 25 mg/kg twice daily also afforded significant protection. Treatment with ribavirin inhibited the growth of influenza virus in the lungs of mice and delayed by about 24 h the attainment of maximal viral titers, which in nontreated mice were reached within 24 to 48 h. Inhibition of viral growth was correlated with a suppression of lung consolidation. Ribavirin appears to exert its protective effects against influenza infections by inhibiting virus growth, thereby preventing virus titers from reaching levels that result in massive lung tissue destruction and death of the mice.

Idiopathic rhabdomyolysis

The clinical, biochemical, and pathological findings in 2 children with idiopathic rhabdomyolysis are reported. Hypocalcaemic tetany, a previously unrecognized complication of severe muscle damage, was seen in one child and was associated with hyperphosphataemia and hyperphosphaturia consequent on the rhabdomyolysis. Respiratory distress and an acute tubular necrosis contributed to her eventual death. The second child recovered; an intracellulr granular material of unknown nature was seen in his muscle biopsy on electron microscopy. The literature of idiopathic recurrent rhabdomyolysis occurring in childhood is reviewed.

Effect of parafunctional clenching on temporomandibular disorder pain and proprioceptive awareness

This study tested the hypothesis that parafunctional clenching increases pain, can lead to a diagnosis of temporomandibular disorder (TMD) pain, and can produce reductions in proprioceptive awareness. Twenty individuals participated in EMG biofeedback training sessions on the left and right temporalis and masseter muscles. No subjects had TMD prior to training. Subjects were randomly assigned to either a Decrease group, who were instructed to maintain EMG activity below 2 microV during training, or an increase group, who were instructed to maintain EMG activity above 10 microV. To test the impact of parafunctional clenching on proprioceptive awareness, all subjects were instructed to barely touch their teeth together while EMG activity was recorded pre- and post-training. Three subjects assigned to the Increase group and no subjects assigned to the Decrease group were diagnosed with TMD pain following training. Self-reported pain post-training was significantly higher for the Increase group. Parafunctional clenching did not affect performance in the proprioceptive test.

Haemoglobin F Victoria Jubilee (alpha 2 A gamma 2 80 Asp-Try)

A new A gamma chain haemoglobin variant, haemoglobin F Victoria Jubilee, with an electrophoretic mobility slightly anodal to haemoglobin F Port Royal, was found in a Jamaican infant. The amino acid residue substitution of 80 Aspartic Acid leads to Tyrosine was associated with alanine in position 136. Haemoglobin F Victoria Jubilee constituted about 7.0 percent of the total haemoglobin F.

Comparison of silver sulphadiazine 1 per cent, silver sulphadiazine 1 per cent plus chlorhexidine digluconate 0.2 per cent and mafenide acetate 8.5 per cent for topical antibacterial effect in infected full skin thickness rat burn wounds

Silver sulphadiazine 1 per cent (SS), silver sulphadiazine 1 per cent plus chlorhexidine digluconate 0.2 per cent (SS + CD 0.2 per cent) and mafenide acetate 8.5 per cent (MA) were compared to assess the antibacterial effect of once daily application on experimental rat 20 per cent full skin thickness burn wounds seeded 24 h earlier with 10(8) microorganisms originally isolated from infected wounds of burned patients. Separate series evaluated Staph. aureus, Enterococcus faecalis, Enterobacter cloacae and Ps. aeruginosa. The mean concentration of all four organisms recovered after 1 week from full thickness biopsies of eschar and from separate biopsies of subjacent muscle was less in MA and SS + CD 0.2 per cent treated animals compared with those treated with SS alone. The mean concentration in muscle and eschar following treatment with MA was less for wounds seeded with Staph. aureus and Ps. aeruginosa than with SS + CD 0.2 per cent treatment, while the mean concentration in eschar application of SS + CD 0.2 per cent was less than with MA for E. faecalis seeded wounds.