Pathology of early-onset Alzheimer's disease cases bearing the Thr113-114ins presenilin-1 mutation

Most cases of familial presenile Alzheimer's disease are caused by mutations in the presenilin-1 (PSEN-1) gene, most of these mutations being missense mutations. A mutation in the splice donor site of intron 4 of PSEN-1 has been described recently which results in aberrant splicing of PSEN-1 mRNA, causing insertion of an additional amino acid, Thr113-114ins, into the protein. We studied the neuropathology of four cases bearing this mutation in an attempt to clarify the pathology of this hereditary form of Alzheimer's disease and to determine whether it differs from other familial forms of the disease. The disease presented as a progressive cognitive decline, myoclonus and seizures developing later in the disease, a feature common to PSEN-1-linked Alzheimer's disease. The course of the disease was relatively rapid, death occurring approximately 6 years after onset. Pathology in the intron 4 cases demonstrated a severe Alzheimer's disease pathology with abundant deposition of ss-amyloid (Ass) 1-42 senile plaques and the formation of neurofibrillary tangles. Amyloid angiopathy was present in these cases and was readily demonstrated by Ass 1-40 staining, particularly in the cerebellum. Cases with the intron 4 mutation appear clinically and pathologically similar to other cases of early-onset Alzheimer's disease bearing PSEN-1 mutations.

Dry-heat sterilization of parenteral oil vehicles

The purpose of this study was to evalutate the effect of temperature and time on the dry-heat sterilization conditions of cottonseed, peanut and sesame-seed oils used as vehicles for parenteral drugs. The three oils were inidividually spiked wiht Bacillus subtilis spores and exposed to dry heat at four temperatures (150, 160, 170, and 180 deg C) for three different time intervals (one, 1.5 and two hours). Following inoculation and dry-heat sterilization, samples were placed in a laminar airflow hood and processed according to 71, "Sterility Tests" of the USP XXIV/NF 19 using thioglycolate broth and fluid D. The specimens were then placed into an incubator at 30 deg C and observed for three, five and seven days for bacterial growth. All tests were performed in triplicate. Positive and negative controls were conducted with each group. All three oils were found to be free of viable Bacillus subtilis following dry-heat sterilization at 150, 160, 170 and 180 deg C for one, 1.5 and two hours after incubation for seven days. The positive controls had no observed bacterial growth. Dry-heat sterilization of the three oils at 150 deg C for one hour appeared to be sufficient for time and temperature conditions. However, the authors recommend dry-heat sterilization procedures be validated for each product.

Planning for successful outcomes in the new millennium

The complexity of the health care environment will increase in the next millennium. Organizations must adopt an approach of selecting outcomes management solutions that are focused on data capture, analysis, and comparative reviews and reporting. They must decisively and creatively implement, in a phased approach, integrated solutions from existing robust systems, while considering future systems targeted for implementation. Outcomes management solutions must be integrated with the organization's information systems strategic plan. The successful organization must be able to turn business-critical data into information that supports both business and clinical decision-making activities. In short, health care organizations will have to become information-driven.

Leveraging technology for success

Many new information systems, technologies, and inventions promise significant benefit and value. Balancing the ever-increasing technology demands and their related expense with provision of high quality cost-effective patient care is one of today's significant organizational challenges. When appropriately deployed, Information Technology can support organizations in achieving their competitive leverage, market position, quality patient care, and efficient operations. This article presents an overview of the impact of new and emerging technologies, and suggests ways organizations can successfully leverage information systems and technology.

Nursing case management in the millennium. Two perspectives

To prepare case managers for the next millennium, Russell Coile, a noted healthcare futurist, and Pamela Matthews, a respected clinician and consultant, participate in a dialogue. Coile takes a broad view of millennial issues, while Matthews responds to those issues with her clinician's perspective. Case management will face challenges and opportunities as a result of internal and external pressures to the healthcare community. These pressures, both near- and far-term, will simultaneously strengthen and tax the case manager's responsibilities. Developments in technology and demands for more and better access to high-quality patient information will require nursing case managers to expand their knowledge of, and influence over, the application of technology and information systems. Case managers will need to participate in advocating, planning, and deploying these systems. Technological challenges will not change case managers' fundamental roles within an organization, but they will strengthen and support those roles by harnessing the information necessary to allow more efficient outcomes, create standards of care, and increase patient satisfaction.

Referral for 'prostatism': developing a 'performance indicator' for the threshold between primary and secondary care?

OBJECTIVE

We aimed to define a performance indicator at the gateway between primary and secondary care.

METHOD

We carried out an analysis of referral letters sent to an urological department within the catchment area of a teaching hospital in Cardiff, Wales. The subjects were 221 sequential referral letters from 221 GPs. The main outcome measures were the information content of referral letters analysed. Letters were stratified into referral threshold groups by the presence of history, examination, routine investigations and specialized investigations.

RESULTS

Three distinct categories of referral practice were identified: referrals which contained history alone; those providing history examination and a selection of routine investigations; and those providing history, examination data and the results of routine and specialized investigations. The study demonstrated that more than a third of GPs do not report the results of digital rectal examination in their referrals and only 4% record urinary flow rates and post-micturition residual urine volume.

CONCLUSIONS

The majority (60%) of generalist referrals to an urology department for prostatism provide enough information for specialists to be able to prioritize appointments, but more than a third (36%) of the referrals contain inadequate information. The method has the potential of being developed into a gateway performance indicator in clinical practice.

Preimplantation genetic diagnosis using fluorescent polymerase chain reaction: results and future developments

PURPOSE

Fluorescent polymerase chain reaction (PCR) is a multipurpose technique that can be used for diagnosing sex, single-gene defects, and trisomies as well as determining DNA fingerprints from single cells. However, its effectiveness must be assessed before clinical preimplantation genetic diagnosis (PGD) application.

METHODS

Single and multiplex fluorescent PCR was applied to single cells and blastomeres.

RESULTS

Fluorescent PCR can be used to diagnose sex from blastomeres and has been successfully applied in a clinical PGD sexing program resulting in a confirmed pregnancy. A further major advantage of fluorescent PCR is the ability to multiplex, providing multiple diagnoses and DNA fingerprints with a high reliability (approximately 75% for trisomy, 86% for DNA fingerprint) and good accuracy (70-80%). Allele dropout in multiplex PCR is approximately 20% per allele and does not appear to be associated with the fragment size.

CONCLUSIONS

Fluorescent PCR is a powerful technique for PGD, and the effects of allele dropout must be considered, particularly in multiplex PCR.

Multiple genetic diagnoses from single cells using multiplex PCR: reliability and allele dropout

We used a multiplex fluorescent PCR system containing seven primer sets on single cells from three different cell types (buccal, corneal and blastomere cells) and more than 3500 heterozygous alleles to investigate reliability and extent of allele dropout in multiplex PCRs at the single cell level. All three cell types gave similarly high reliability, accuracy and allele dropout rates, with similar reliability between singleplex and multiplex PCRs. Allele dropout was also consistent between the three cell types and did not significantly increase as allele size increased. These results indicate that multiplex fluorescent PCR is a reliable and accurate method of obtaining multiple diagnosis (eight chromosomes simultaneously) from single cells and maximizes the information available from single cell analysis.

Case management information systems: how to put the pieces together now and beyond year 2000

Healthcare organizations must establish the goals and objectives of their case management processes before functional and system requirements can be defined. A gap analysis will identify existing systems that can be used to support case management as well as areas in need of systems support. The gap analysis will also identify short-term tactical projects and long-term strategic initiatives supporting the automation of case management. The projects resulting from the gap analysis must be incorporated into the organization's business and information systems plan and budget to ensure appropriate funding and prioritization.

Multiple genetic diagnoses from single cells using multiplex PCR: reliability and allele dropout

We used a multiplex fluorescent PCR system containing seven primer sets on single cells from three different cell types (buccal, corneal and blastomere cells) and more than 3500 heterozygous alleles to investigate reliability and extent of allele dropout in multiplex PCRs at the single cell level. All three cell types gave similarly high reliability, accuracy and allele dropout rates, with similar reliability between singleplex and multiplex PCRs. Allele dropout was also consistent between the three cell types and did not significantly increase as allele size increased. These results indicate that multiplex fluorescent PCR is a reliable and accurate method of obtaining multiple diagnosis (eight chromosomes simultaneously) from single cells and maximizes the information available from single cell analysis.

Same day diagnosis of Down's syndrome and sex in single cells using multiplex fluorescent PCR

The major reason for prenatal diagnosis lies in the detection of trisomies, particularly trisomy 21 (Down's syndrome). Current techniques require lengthy laboratory procedures and high costs. Furthermore, diagnosis is often not possible if the sample is of small size or is contaminated. An alternative method, quantitative fluorescent polymerase chain reaction (PCR) of short tandem repeats (STRs), can also be used to diagnose trisomies and it has the advantage that a result is obtained within five to eight hours. However, this method is currently limited to relatively large amounts of sample, which restricts diagnostic confidence and value. Recently, genetic diagnosis using fluorescent PCR has been applied at the single cell level but is limited to sex or single gene defect diagnosis. This study, using quantitative multiplex fluorescent PCR, provides for the first time simultaneous diagnosis and confirmation of sex and trisomy in single cells. Two markers for chromosome 21 increase diagnostic confidence, informativeness, and confirmation. This system is rapid (five hours), reliable, and accurate and we believe that it will be more cost effective than alternative methods. The technique has direct application to preimplantation genetic diagnosis, early prenatal diagnosis, and other diagnostic systems where sample size is limited.

Rapid trisomy diagnosis (21, 18, and 13) using fluorescent PCR and short tandem repeats: applications for prenatal diagnosis and preimplantation genetic diagnosis

PURPOSE AND METHODS

Prenatal diagnosis of fetal trisomies is usually performed by cytogenetic analysis from amniotic fluid. This requires lengthy laboratory procedures and high costs and is unsuitable for large-scale screening of pregnant women. An alternative method, which is rapid and inexpensive and may potentially be suitable for diagnosing trisomies even from single fetal cells, is the fluorescent polymerase chain reaction (F-PCR) using polymorphic small tandem repeats (STRs).

RESULTS

In this paper we present data demonstrating that fluorescent PCR amplification of STRs can be used for rapid diagnosis of trisomy 21, trisomy 18, and trisomy 13 and can be successfully applied to both prenatal diagnosis and diagnosis of single cells. This study also reports significant numbers of prenatal diagnoses using quantitative fluorescent PCR.

CONCLUSIONS

We believe that further studies of greater numbers of samples will determine the absolute reliability of this technique. These results also provide a model for trisomy diagnosis from single cells using multiple STR markers for either preimplantation genetic diagnosis or, potentially, diagnosis from fetal cells isolated from maternal blood.

Rapid determination of trisomy 18 parental origin using fluorescent PCR and small tandem repeat markers: case reports

Trisomy 18 is the second most common genetic defect after trisomy 21, almost 90% of which are due to additional chromosome from the mother. The parental origin of the additional chromosome can, if required, be determined by two methods: karyotyping, which takes several weeks; or, more recently, by polymerase chain reaction (PCR) which is often problematic. Fluorescent PCR of small tandem repeats (STRs) can determine the parental origin in the majority of cases within 5 h. Although the incidence of paternal origin is known for both trisomy 21 and trisomy 18, this technique can rapidly determine the parental origin in cases where there is insufficient samples to perform conventional tests. Determining parental origin by these methods may also have clinical significance in the diagnosis of chromosomal translocations or in the diagnosis of genetic disease using linkage analysis.

Affinity purification of RNA: sequence-specific capture by nonionic morpholino probes

Nucleic acid isolation for amplification-based diagnostics requires techniques that do not co-purify inhibitors of DNA polymerases. Also, other requirements for an ideal sample preparation technology include ease of use, capability for automation, high recovery and the use of nontoxic reagents. Affinity purification techniques provide high purification factor with minimal sample processing. Hybridization is the affinity interaction specific to nucleic acids and thus provides a uniquely advantageous method for purifying DNA or RNA for subsequent manipulation. Nonionic (morpholino) probes (Neu-Probes, AntiVirals, Corvallis, OR, USA) have several unique hybridization properties, including resistance to nucleases and the ability to hybridize independently of salt concentration. Therefore, such probes provide advantages over DNA probes for sample preparation by hybridization capture. Three formats for hybridization-based purification of human immunodeficiency virus (HIV) RNA were evaluated using RNA transcripts spiked into crude lysates of normal human plasma. Indirect capture used streptavidin-coated microparticles to capture hybrids of biotinylated capture probes and HIV RNA. Direct capture used particles precoated with probes. In addition, a novel method for acceleration of sequence-specific hybridization was developed and shown to give consistently high recoveries.

Bone conduction implants for amplification: comparison of results

We compared the results from the North American patient database on the Xomed Audiant Bone Conductor to those reported on the NobleBiocare (previously Noblepharma) HC200 bone-anchored hearing aid (BAHA) implant, using the literature and specific results provided by one of the authors. It has been proposed that the percutaneous coupling of the NobleBiocare implant transduces energy more powerfully than the Audiant transcutaneous coupling. If true, percutaneous coupling could provide greater amplification, helping patients experiencing both conductive and sensorineural hearing loss. Aided sound-field thresholds corresponding to bone-conduction thresholds were compared retrospectively through the speech frequencies. Both the BAHA and the Audiant devices amplified in the sound field to approximate preoperative bone-conduction thresholds. No statistically significant differences existed between the amplification of warble tones through the speech frequencies for either device. We conclude that amplification with the Audiant device offers as much gain as the HC200 device through the speech frequencies. While both devices can supply effective amplification for select patients suffering from conductive hearing loss, neither provides gain superior to preoperative bone-conduction thresholds to address the needs of select patients with a substantial sensorineural component.

UNIFOLIATA regulates leaf and flower morphogenesis in pea

BACKGROUND

The vegetative phenotype of the pea mutant unifoliata (uni) is a simplification of the wild-type compound leaf to a single leaflet. Mutant uni plants are also self-sterile and the flowers resemble known floral meristem and organ identity mutants. In Antirrhinum and Arabidopsis, mutations in the floral meristem identity gene FLORICAULA/LEAFY (FLO/LFY) affect flower development alone, whereas the tobacco FLO/LFY homologue, NFL, is expressed in vegetative tissues, suggesting that NFL specifies determinacy in the progenitor cells for both flowers and leaves. In this paper, we characterised the pea homologue of FLO/LFY.

RESULTS

The pea cDNA homologue of FLO/LFY, PEAFLO, mapped to the uni locus in recombinant-inbred mapping populations and markers based on PEAFLO cosegregated with uni in segregating sibling populations. The characterisation of two spontaneous uni mutant alleles, one containing a deletion and the other a point mutation in the PEAFLO coding sequences, predicted that PEAFLO corresponds to UNI and that the mutant vegetative phenotype was conferred by the defective PEAFLO gene.

CONCLUSIONS

The uni mutant demonstrates that there are shared regulatory processes in the morphogenesis of leaves and flowers and that floral meristem identity genes have an extended role in plant development. Pleiotropic regulatory genes such as UNI support the hypothesis that leaves and flowers derive from a common ancestral sporophyll-like structure. The regulation of indeterminancy during leaf and flower morphogenesis by UNI may reflect a primitive function for the gene in the pre-angiosperm era.

Morpholino and phosphorothioate antisense oligomers compared in cell-free and in-cell systems

Morpholino and phosphorothioate (S-DNA) antisense oligos were compared in both cell-free and in-cell translation systems. In the most stringent test of specificity in the cell-free system, a globin-targeted S-DNA oligo was found to inhibit its target sequence at concentrations of 10 nM and above, but the sequence-specific component of this inhibition dropped below 50% at concentrations of 100 nM and above. A corresponding Morpholino oligo achieved even higher inhibition at 10 nM, but in contrast to the S-DNA, with the Morpholino, the sequence-specific component of this inhibition remained above 93% at a concentration of 3000 nM. In this same cell-free test system, several S-DNA oligos exhibited substantial undesired nonantisense effects at concentrations of 300 nM and above, whereas corresponding Morpholino oligos exhibited little or no nonantisense activity through a concentration of 3000 nM. In scrape-loaded HeLa cells, both globin-targeted and HBV-targeted S-DNAs (both antisense and control oligos) generally failed to achieve significant translational inhibition at extracellular concentrations up to 3000 nM. In contrast, the Morpholino oligos achieved effective and specific translational inhibition at extracellular concentrations ranging from 30 nM to 3000 nM.

Cloning of a rice cDNA encoding a transcription factor homologous to barley GAMyb

A cDNA clone, OsGAmyb, which encodes a homologue to the barley Myb-like transcription factor, HvGAMyb, was isolated from a rice endosperm cDNA library. The clone was used to show that expression of the OsGAmyb gene in aleurone cells was stimulated by gibberellic acid and the gene product was shown to transactivate an alpha-amylase gene promoter in transient expression analyses.