Synthesis of alpha-amino-alpha'-diazomethyl ketones via ring opening of substituted cyclopropanones with alkyl azides. A facile route to N-substituted 3-azetidinones

[reaction: see text] The reaction of alkyl azides with triethyl(1-methoxy-2, 2-dimethyl-cyclopropoxy)silane affords a series of alpha-amino-alpha'-diazomethyl ketones in moderate yields (38-54%). The mechanism of this novel process is discussed. The diazomethyl ketones could also be cyclized to the corresponding N-substituted 3-azetidinones in good yield upon treatment with Rh(2)(OAc)(4).

The deficit in cataract surgery in England and Wales and the escalating problem of visual impairment: epidemiological modelling of the population dynamics of cataract

BACKGROUND

The pool of old cases of cataract, the expected new cases, and the shortfall in cataract surgery and consequently the numbers dying with poor vision without the benefit of cataract surgery are regarded as escalating problems worldwide. Successive governments and the professional ophthalmic bodies have not had the wherewithal to estimate the magnitude or interaction of these elements in the population of the UK. This study has collected and applied the best available epidemiological data on cataract prevalence, incidence and service utilisation, and demography to address the problem of control of the cataract pool in the population of England and Wales.

METHODS

Data from recent surveys undertaken by the authors, both on prevalence of vision impairing cataract and on patterns of cataract surgery, were used together with demographic and service utilisation information obtained from government departments. These were integrated within a holistic model, which was run under varied assumed levels and patterns of service provision.

RESULTS

The study shows that there is a serious pool of unoperated vision impairing cataract in the population aged 65 and older, reflecting a shortfall in cataract surgery. Continuing with the present level and pattern of service provision, the pool will increase to over 2.5 million by the year 2001. In addition, more than 700 000 will die with unoperated impaired vision.

CONCLUSIONS

Targeting of existing or new additional operations to those below the visual acuity of 6/12 will have relatively little effect on numbers dying without surgery, but should have a substantial controlling effect on the pool of vision impairing cataract in the population.

Acute thrombotic-ischemic coronary syndromes: the usefulness of TEC

Transluminal extraction catheter (TEC) is a percutaneous device that performs simultaneous thrombus aspiration and plaque excision. Clinical indications for its application are acute myocardial infarction, unstable angina, and stable angina caused by atherosclerotic, thrombotic lesions located within native coronary arteries and degenerated saphenous vein grafts. The device is useful in management of ischemic patients with contraindications to either pharmacologic thrombolytics or platelet GPIIb/IIIa receptor inhibitors, and can also effectively be used in combination with these agents. A successful TEC procedure requires careful patient selection, strict adherence to recommended indications, optimal equipment selection, familiarity with mechanical components of the device, full understanding of safe and efficacious techniques for deployment and activation, as well as recognition of unique associated angiographic manifestations such as the "empty-pouch phenomenon." As with other debulking devices, the incidence of restenosis post-TEC appears to be directly related to acute luminal gain at the time of procedure and therefore requires the need for adjunct stenting. This communication describes and illustrates various clinical, technical, and angiographic aspects of TEC procedure in patients with acute ischemic-thrombotic coronary syndromes. Cathet. Cardiovasc. Intervent. 48:406-420, 1999.

National cataract surgery survey 1997-8: a report of the results of the clinical outcomes

AIMS

A national survey of over 100 hospitals in the UK was carried out to collect routine clinical information on the outcomes of cataract surgery. The clinical outcomes of interest were: visual acuity at time of discharge from postoperative hospital follow up, visual acuity at time of final refraction; complications related to surgery occurring during the operation, within 48 hours of surgery, and within 3 months of surgery. In addition, information on age and comorbidity was obtained. This article reports on the findings of the experience of approximately 18 000 patients who had cataract surgery in the hospital eye service of the NHS.

RESULTS

Of those with no ocular comorbidity, 85% achieved a visual acuity of 6/12 or better on discharge from postoperative hospital follow up, while 65% of patients with a serious co-existing eye disease achieved this level of acuity at this time. At final refraction, 92% of patients without ocular comorbidity and 77% of patients with ocular comorbidity achieved 6/12 or better visual acuity. The following main risk indicators were associated with visual outcomes and complications related to surgery: age, other eye diseases, diabetes and stroke, type of surgical procedure, and grade of surgeon.

CONCLUSIONS

The acceptability of these findings could fruitfully be the subject of discussion within the ophthalmic community and hopefully issues arising out of the study can lead to research, especially in-depth studies of the outcomes of cataract surgery in those patients with co-existing serious eye conditions.

Second site mutations in the N-terminus of the major capsid protein (VP5) overcome a block at the maturation cleavage site of the capsid scaffold proteins of herpes simplex virus type 1

VP5, the major capsid protein of herpes simplex virus type 1 (HSV-1), interacts with the C-terminal residues of the scaffold molecules encoded by the overlapping UL26 and UL26.5 open reading frames. Scaffold molecules are cleaved by a UL26 encoded protease (VP24) as part of the normal capsid assembly process. In this study, residues of VP5 have been identified that alter its interaction with the C-terminal residues of the scaffold proteins. A previously isolated virus (KUL26-610/611) was used that encoded a lethal mutation in the UL26 and UL26.5 open reading frames and required a transformed cell line that expresses these proteins for virus growth. The scaffold maturation cleavage site between amino acids 610 and 611 was blocked by changing Ala-Ser to Glu-Phe, which generated a new EcoRI restriction site. Revertant viruses, that formed small plaques on nontransformed cells, were detected at a frequency of 1:3800. Nine revertants were isolated, and all of them retained the EcoRI site and therefore were due to mutations at a second site. The second site mutations were extragenic. Using marker-transfer techniques, the mutation in one of the revertants was mapped to the 5' region of the gene encoding VP5. DNA sequence analysis was performed for the N-terminal 571 codons encoding VP5 for all of the revertant viruses. Six of the nine revertants showed a single base pair change that caused an amino acid substitution between residues 30 and 78 of VP5. Three of these were identical and changed Ala to Val at residue 78. The data provide a partial map of residues of VP5 that alter its interaction with scaffold proteins blocked at their normal cleavage site. The yeast two-hybrid system was used as a measure of the interaction between mutant VP5 and scaffold molecules and varied from 11% to nearly 100%, relative to wild-type VP5. One revertant gave no detectable interaction by this assay. The amount of UL26 encoded protease (VP24) in B capsids for KUL26-610/611 and for revertants was 7% and 25%, respectively, relative to the amount in capsids for wild-type virus. The lack of retention of the viral protease in the mutant virus and a fourfold increase for the revertants suggest an additional essential function for VP24 in capsid maturation, and a role in DNA packaging is indicated.

Indium-111-oxine labeled leukocyte uptake in Ki-1-positive anaplastic large cell lymphoma

Indium-111-oxine labeled leukocyte ((111)In-WBC) scintigraphy is well known for its ability to localize in areas of active infection, but not in areas of lymphomatous involvement. We present a case of Ki-1-positive anaplastic large-cell lymphoma that was initially thought to be a case of multifocal osteomyelitis because of positive uptake on a (111)In-WBC scan. The areas of abnormal uptake on the indium scan were demonstrated histopathologically to be sites of lymphomatous involvement in bone.

Profile of patients presenting for cataract surgery in the UK: national data collection

AIMS/METHODS

A national data collection exercise was carried out in more than 100 hospital eye service units within the UK to provide clinical and administrative information on patients undergoing cataract surgery. This included patient clinical data such as visual acuity at the time of wait listing and at the time of admission for surgery, presence of other eye disorders, other serious medical disorders, and data on waiting time and type of admission.

RESULTS

The profiles of the 18 454 patients aged 50 years or older are reported. Findings of particular note were as follows. At the time of wait listing for cataract surgery 31% had visual acuity of 6/12 or better, 54% had visual acuity between 6/18 and 6/60, and 15% had less than 6/60 vision. Considering those who had visual acuity of 6/12 or better at the time of wait listing, by the time of admission for surgery, the vision deteriorated to 6/18-6/60 in 33% and in a further 3% the vision deteriorated to below 6/60. In patients with moderately poor visual acuity (<6/12-6/60) at the time of wait listing, 13% had less than 6/60 vision by the time of admission for surgery.

CONCLUSION

This type of data collection and reporting exercise provides new material that can be used in the planning and provision of cataract surgery services in the UK.

Eye injuries in children: the current picture

AIMS

To investigate the current causes and outcomes of paediatric ocular trauma.

METHODS

A prospective observational study of all children admitted to hospital with ocular trauma in Scotland over a 1 year period.

RESULTS

The commonest mechanism of injury was blunt trauma, accounting for 65% of the total. 60% of the patients were admitted with a hyphaema. Injuries necessitating admission occurred most frequently at home (51%). Sporting activities were the commonest cause of injury in the 5-14 age group. There were no injuries caused by road traffic accidents or fireworks. Patients were admitted to hospital for a mean of 4.2 days (range 1-25 days). One (1%) child had an acuity in the "visually impaired" range (6/18-6/60) and one (1%) was "blind" (6/60) in the affected eye. No child was bilaterally blinded by injury and none required blind or partial sight registration.

CONCLUSION

This study has shown that the incidence of eye injuries affecting children has fallen. The outcome of ocular trauma has improved significantly, and for the first time paediatric injuries appear to have a better prognosis than injuries affecting adults.

The role of intraoperative Gram stain in revision total joint arthroplasty

The ability to identify intraoperatively patients with an infected prosthesis at the time of a revision procedure assists the surgeon in selecting appropriate management. The results of 413 intraoperative Gram stains were compared with the results of operative cultures, permanent histology, and the surgeon's intraoperative assessment to determine the ability of Gram stains to identify periprosthetic infection. Gram staining correctly identified the presence of infection in 10 of the 68 cases that met study criteria for infection (sensitivity of 14.7%). Four false-positive Gram stains were encountered. Intraoperative Gram stains do not have adequate sensitivity to be helpful in identifying periprosthetic infection and should not be performed on a routine basis. They may be helpful, however, in cases in which gross purulence is encountered to assist in the selection of initial antibiotic therapy. The use of intraoperative Gram staining alone is inadequate for ruling out infection at the time of revision total joint arthroplasty.

Calculation of relative binding free energy difference of DHFR inhibitors by a finite difference thermodynamic integration (FDTI) approach

We have implemented a Finite Difference Thermodynamic Integration (FDTI) approach to estimate the binding free energy relative to methotrexate (MTX) of three unreported inhibitors of DHFR. The validity of the calculation methodology was first proved by evaluating the relative binding free energy difference for two well-known anticancer agents aminopterin and methotrexate. The usefulness of the method in drug design has been demonstrated by the fact that inhibitor 5, designed by us was found to bind more tightly than MTX, by as much 7.5 kcal/mole and is a worthy candidate for further pharmacological investigations.

Analysis of frozen sections of intraoperative specimens obtained at the time of reoperation after hip or knee resection arthroplasty for the treatment of infection

BACKGROUND

Despite the effectiveness of a two-stage exchange protocol for the treatment of deep periprosthetic infection, infection can persist after resection arthroplasty and treatment with antibiotics, leading to a failed second-stage reconstruction. Intraoperative analysis of frozen sections has been shown to have a high sensitivity and specificity for the identification of infection at the time of revision arthroplasty; however, the usefulness of this test at the time of reoperation after resection arthroplasty and treatment with antibiotics is, to our knowledge, unknown.

METHODS

The medical records of sixty-four consecutive patients who had had a resection arthroplasty of either the knee (thirty-three patients) or the hip (thirty-one patients) and had had intraoperative analysis of frozen sections of periprosthetic tissue obtained at the time of a second-stage operation were reviewed. The mean interval between the resection arthroplasty and the attempted reimplantation was nineteen weeks. The results of the intraoperative analysis of the frozen sections were compared with those of analysis of permanent histological sections of the same tissues and with those of intraoperative cultures of specimens obtained from within the joint. The findings of the analyses of the frozen sections and the permanent histological sections were considered to be consistent with acute inflammation and infection if a mean of ten polymorphonuclear leukocytes or more per high-power field (forty times magnification) were seen in the five most cellular areas.

RESULTS

The intraoperative frozen sections of the specimens from two patients (one of whom was considered to have a persistent infection) met the criteria for acute inflammation. Four patients were considered to have a persistent infection on the basis of positive intraoperative cultures or permanent histological sections. Overall, intraoperative analysis of frozen sections at the time of reimplantation after resection arthroplasty had a sensitivity of 25 percent (detection of one of four persistent infections), a specificity of 98 percent, a positive predictive value of 50 percent (one of two), a negative predictive value of 95 percent, and an accuracy of 94 percent.

CONCLUSIONS

A negative finding on intraoperative analysis of frozen sections has a high predictive value with regard to ruling out the presence of infection; however, the sensitivity of the test for the detection of persistent infection is poor.

Medical evaluation of Persian Gulf veterans with fatigue and/or chemical sensitivity

The purpose of this study was to determine if Gulf War veterans with complaints of severe fatigue and/or chemical sensitivity (n = 72) fulfill case definitions for chronic fatigue syndrome (CFS) and/or multiple chemical sensitivity (MCS) and to compare the characteristics of those veterans who received a diagnosis of CFS (n = 24) to a group of non-veterans diagnosed with CFS (n = 95). Thirty-three veterans received a diagnosis of CFS with 14 having MCS concurrently; an additional six had MCS but did not fulfill a case definition for CFS. The group of fatigued veterans receiving a diagnosis of CFS was comprised of significantly fewer women and fewer Caucasians than the civilian group, and significantly fewer veterans reported a sudden onset to their illness. Veterans with CFS had a milder form of the illness than their civilian counterparts based on medical examiner assessment of the severity of the symptoms, reported days of reduced activity, and ability to work. Since CFS in veterans seems less severe than that seen in civilians, the prognosis for recovery of veterans with this disorder may be better.

Alternative medicine: old ideas with new interests?

The use of complementary or alternative medicine has greatly increased in developed countries during the last few years. In such countries, laws have been passed and regulations made to protect both the public and the practitioners. There are a growing number of research units in universities, journals, and associations of practitioners of complementary medicine. In Jamaica, too, there is increasing recognition, if not acceptance, of the popular interest in complementary medicine. In preparation for the next century we will need to address some of the legal, educational and scientific issues raised.

Incorporation of the green fluorescent protein into the herpes simplex virus type 1 capsid

The herpes simplex virus type 1 (HSV-1) UL35 open reading frame (ORF) encodes a 12-kDa capsid protein designated VP26. VP26 is located on the outer surface of the capsid specifically on the tips of the hexons that constitute the capsid shell. The bioluminescent jellyfish (Aequorea victoria) green fluorescent protein (GFP) was fused in frame with the UL35 ORF to generate a VP26-GFP fusion protein. This fusion protein was fluorescent and localized to distinct regions within the nuclei of transfected cells following infection with wild-type virus. The VP26-GFP marker was introduced into the HSV-1 (KOS) genome resulting in recombinant plaques that were fluorescent. A virus, designated K26GFP, was isolated and purified and was shown to grow as well as the wild-type virus in cell culture. An analysis of the intranuclear capsids formed in K26GFP-infected cells revealed that the fusion protein was incorporated into A, B, and C capsids. Furthermore, the fusion protein incorporated into the virion particle was fluorescent as judged by fluorescence-activated cell sorter (FACS) analysis of infected cells in the absence of de novo protein synthesis. Cells infected with K26GFP exhibited a punctate nuclear fluorescence at early times in the replication cycle. At later times during infection a generalized cytoplasmic and nuclear fluorescence, including fluorescence at the cell membranes, was observed, confirming visually that the fusion protein was incorporated into intranuclear capsids and mature virions.

Herpes simplex virus type 1 VP26 is not essential for replication in cell culture but influences production of infectious virus in the nervous system of infected mice

VP26 is the smallest capsid protein of herpes simplex virus type 1 and is encoded by the UL35 open reading frame. It resides on the outer capsid surface, interacting with VP5 in a one to one stoichiometry in the hexons that comprise capsids. A null mutation in the gene encoding VP26 was generated and transferred into the KOS genome. Recombinant viruses were isolated on Vero cells, which indicated that the absence of VP26 was not required for growth of the virus in cell culture. This was confirmed by the characterization of the VP26 null mutant, designated K delta 26Z. The yield of virus from K delta 26Z-infected Vero cells was decreased only twofold relative to wild-type-infected cells, as judged by the burst size. All three types of capsids (A, B, and C) were observed after sedimentation analysis of K delta 26Z-infected cell extracts. These capsids were similar in composition to wild-type capsids except for the absence of VP26. The mouse ocular model was used to determine if VP26 played a major role in vivo. The yield of the mutant virus relative to wild-type virus was decreased twofold in the eye; however, the mutant virus yields were decreased 30- to 100-fold in the trigeminal ganglia. Reactivation of the mutant virus as determined by cocultivation assays was also reduced. To determine the effect of VP26 on capsid translocation, the VP26 null mutation was transferred into a virus specifiying a thymidine kinase mutation that by itself is transported to the trigeminal ganglia but whose DNA is not replicated in the ganglia. Using quantitative PCR assays the number of viral genomes detected in the ganglia was similar in the presence or the absence of VP26. Therefore, VP26 does not appear to aid in the translocation of the virus capsid from the mouse eye to the trigeminal ganglia but is important for infectious virus production in the ganglia.

Prevalence of serious eye disease and visual impairment in a north London population: population based, cross sectional study

OBJECTIVE

To estimate the magnitude of serious eye disorders and of visual impairment in a defined elderly population of a typical metropolitan area in England, and to assess the frequency they were in touch with, or known to, the eye care services.

DESIGN

Cross sectional survey using two stage cluster random sampling.

SETTING

General practices in north London.

SUBJECTS

Random sample of people aged 65 and older, drawn from a defined population of elderly people registered with 17 general practice groups.

MAIN OUTCOME MEASURES

Proportions and population prevalence estimates were determined for visual acuity, assessed with the person's own spectacles (if any), classified into four categories: prevalence of cataract, age related macular degeneration, and refractive error causing visual impairment and of definite primary open angle glaucoma; and status of contact with eye services.

RESULTS

1547 of 1840 (84%) eligible people were examined. The population prevalence of bilateral visual impairment (visual acuity <6/12) was 30%, of which 72% was potentially remediable. 92 of these 448 cases (21%) had visual acuity <6/60 ("blindness") in one or both eyes. Prevalence of cataract causing visual impairment was 30%; 88% of these people were not in touch with the eye services. The prevalence of vision impairing, age related macular degeneration was 8% and of glaucoma (definite cases) was 3%. Three quarters of the people with definite glaucoma were not known to the eye services.

CONCLUSIONS

Untreated visual impairment and eye disorders affect a substantial proportion of people aged 65 years and older. These findings should contribute to the setting up of future strategies for preservation of sight and eye health services in general.