An audit into homeless families in temporary accommodation

This article describes a clinical audit project undertaken in a number of hostels providing temporary housing for homeless families and individuals in Hinckley, Leicestershire. The audit, carried out over a 6-week period, aimed to collect information about the health and social needs of the residents in the hostels to determine whether an on-site dedicated health visiting service would be of any benefit to them. Family members housed in three council-run hostels were interviewed and a detailed questionnaire was completed. This was used to gather information about the facilities in the hostels, the nutritional and mental status and health and social needs of the residents, the uptake of childhood immunizations and child health surveillance. It also provided information about the resident families' contact with their family health visitor. Families were living in cramped conditions with shared facilities and no safe play areas for their children. The audit clearly demonstrated that the residents living in the hostels had a range of health problems similar to those described in the literature about the homeless. As a result of the audit, a number of recommendations were made which are discussed in this article.

Evaluation and validation of virus removal by ultrafiltration during the production of diaspirin crosslinked haemoglobin (DCLHb)

Virus retention during ultrafiltration through A/G Technology filter cartridges was investigated to characterize the removal process and validate the degree of virus titre reduction during the filtration of red blood cell haemolysates performed as part of the production of diaspirin crosslinked haemoglobin (DCLHb). When viruses were suspended in phosphate buffered saline solution, retention was greater with larger sized viruses and smaller filter pore size. Virus titre was maintained at starting levels in the filter retentate circuit during the course of filtration, suggesting that the virus removal mechanism is predominantly size exclusion. Evaluation of specific processing variables indicated that the retention of phiX174 virus was increased in the presence of red blood cell haemolysate or at high membrane crossflow rates and transmembrane pressures, while the retention of EMC virus was less sensitive to variations in these parameters. Using these results to design a validation protocol, log reduction values of >7.9 were demonstrated for the retention of human immunodeficiency virus, pseudorabies virus and bovine viral diarrhoea viruses, 7.6 for hepatitis A virus, and 4.2 for porcine parvovirus. It was also shown that the retention of viruses was maintained during repetitive use of the same filter cartridge.

Calcium supplements and colorectal adenomas. Polyp Prevention Study Group

Experimental and observational findings suggest that calcium intake may protect against colorectal neoplasia. To investigate this hypothesis, we conducted a randomized, double-blind trial of colorectal adenoma recurrence. Nine hundred thirty patients with a recent history of colorectal adenomas were randomly given calcium carbonate (3 gm daily; 1200 mg elemental calcium) or placebo, with follow-up colonoscopies one and four years after the qualifying examination. The main analysis focused on new adenomas found after the first follow-up endoscopy, up to (and including) the second follow-up examination. Risk ratios of at least one recurrent adenoma and ratios of the average numbers of adenomas were calculated as measures of calcium effect. There was a lower risk of recurrent adenomas in subjects assigned calcium. Eight hundred thirty-two patients had two follow-up examinations and were included in the main analysis; the adjusted risk ratio of one or more adenomas was 0.81 (95% CI 0.67 to 0.99); the adjusted ratio of the average numbers of adenomas was 0.76 (95% CI 0.60 to 0.96). Among subjects who had at least one follow-up colonoscopy, the adjusted risk ratio of one or more recurrent adenomas was 0.85 (95% CI 0.74 to 0.98). The effect of calcium seemed independent of initial dietary fat and calcium intake. No toxicity was associated with supplementation. These findings indicate that calcium supplementation has a modest protective effect against colorectal adenomas, precursors of most colorectal cancers.

Pramlintide, a synthetic analog of human amylin, improves the metabolic profile of patients with type 2 diabetes using insulin. The Pramlintide in Type 2 Diabetes Group

OBJECTIVE

To examine the effects of 4 weeks of subcutaneous administration of pramlintide, a synthetic analog of human amylin, on metabolic control in patients with type 2 diabetes using insulin.

RESEARCH DESIGN AND METHODS

Serum fructosamine, HbA1c, and fasting plasma lipids were measured in 203 patients in a randomized double-blind placebo-controlled parallel-group multicenter trial using doses of 30 micrograms q.i.d., 60 micrograms t.i.d., and 60 micrograms q.i.d.

RESULTS

Statistically significant reductions in serum fructosamine concentrations were observed in the pramlintide 30 micrograms q.i.d. group (17.5 +/- 4.9 mumol/l, P = 0.029), the pramlintide 60 micrograms t.i.d. group (24.1 +/- 4.9 mumol/l, P = 0.003), and the 60 micrograms q.i.d. group (22.6 +/- 4.1 mumol/l, P = 0.001) compared with the placebo group (3.5 +/- 3.8 mumol/l). There were also statistically significant shifts in the proportion of patients with an abnormal serum fructosamine concentration at baseline that normalized at week 4 within the pramlintide 60 micrograms t.i.d. group and the 60 micrograms q.i.d. group. Consistent with the fructosamine results, there were statistically significant reductions in HbA1c in the pramlintide 30 micrograms q.i.d. group (0.53 +/- 0.07%, P = 0.0447), the pramlintide 60 micrograms t.i.d. group (0.58 +/- 0.07%, P < 0.0217), and the pramlintide 60 micrograms q.i.d. group (0.51 +/- 0.08%, P = 0.0242) compared with the placebo group (0.27 +/- 0.08%). Total cholesterol concentrations were also statistically significantly reduced in both the pramlintide 60 micrograms t.i.d. group (8.4 mg/dl, P < 0.01) and 60 micrograms q.i.d. group (10.5 mg/dl, P < 0.01) compared with placebo (1.2 mg/dl). Body weight decreased in both of the pramlintide 60 micrograms groups, but the trend did not achieve statistical significance. The incidence of hypoglycemia was similar in all treatment groups.

CONCLUSIONS

Reductions in serum fructosamine, plasma total and LDL cholesterol concentrations, and HbA1c support the hypothesis that pramlintide may improve metabolic control in patients with type 2 diabetes using insulin.

Effects of 4 weeks' administration of pramlintide, a human amylin analogue, on glycaemia control in patients with IDDM: effects on plasma glucose profiles and serum fructosamine concentrations

The effects of 4 weeks' administration of pramlintide, an analogue of the human hormone amylin, on blood glucose control in 215 patients with insulin-dependent diabetes mellitus were examined in a 4-week, randomized, double-blind, placebo-controlled, parallel-group trial. Pramlintide was administered subcutaneously prior to meals in four dosing regimens: 30 microg four times per day (breakfast, lunch, dinner, and evening snack), 30 microg three times per day (breakfast, lunch and dinner [BLD]), 30 microg three times per day (breakfast, dinner and evening snack [BDS]), and 60 microg twice per day (breakfast and dinner). After 4 weeks of pramlintide 30 microg four times per day administration, there was a statistically significant reduction in the mean 24 h plasma glucose concentration when compared to placebo (-1.4 +/- 0.5 vs 0.3 +/- 0.5 micromol/l, p = 0.009). Serum fructosamine concentrations were reduced 62 +/- 10 micromol/l in the pramlintide 30 mg four times per day group, 43 +/- 7 micromol/l in the pramlintide 30 microg three times per day (BLD) group, 47 +/- 6 micromol/l in the pramlintide 30 microg three times per day (BDS) group, 46 +/- 7 micromol/l in the pramlintide 60 microg twice per day group, and 29 +/- 8 micromol/l by placebo. The incidence of hypoglycaemia was not different in any pramlintide group compared to the placebo group. Nausea, the most frequent adverse event, subsided after the first week of treatment in the majority of patients. In conclusion, pramlintide improved blood glucose control over a 4-week period without increased hypoglycaemia and was well tolerated. Future studies using a longer period of pramlintide administration with assessment of HbA1c as the measurement of glycaemic control are warranted.

Validation of the heat treatment step used in the production of diaspirin crosslinked hemoglobin (DCLHb) for viral inactivation--effect of crosslinking

Two experiments were performed to assess viral inactivation during the crosslinking and heat treatment steps of the DCLHb manufacturing process. Stroma free hemoglobin (SFHb) collected from a large scale manufacturing lot was tested in a 1:680 scaled down system in which the key parameters used in the manufacturing process were replicated. In the first study Porcine Parvovirus (PPV), a non-enveloped virus, was used to assess inactivation, while in the second study Bovine Viral Diarrhea Virus (BVDV), an enveloped virus, was utilized. In both experiments, the SFHb solution was deoxygenated and an aliquot of virus suspension was added. To initiate the crosslinking reaction, a solution of bis (3,5-dibromosalicyl) fumarate (DBBF) in HEPES buffer was added to the test solution. In both experiments the reaction times and the degree of crosslinking were normal. After crosslinking, the reaction mixtures were heated to 74 +/- 1 degrees C over 30 minutes, held at 74 +/- 1 degrees C for 90 minutes, and cooled to less than 10 degrees C over 30 minutes. In each experiment the degree of crosslinking of final product was 100% and yield of hemoglobin recovery was normal. Samples were removed prior to crosslinking, after crosslinking and before, during and after heat treatment for determination of virus titer and evaluation of key process parameters. The results from these experiments were consistent with those obtained from the full scale manufacturing process for the deoxygenation, crosslinking and the heat treatment step during the production of DCLHb. The results of virus assays showed that crosslinking has no effect on viruses and their subsequent inactivation by heat treatment.

Family-centered care and the anticipated death of a newborn

Providing support for a family whose infant is expected to die requires planning and coordinated intervention by members of the health care team. From diagnosis until the death of the infant, the family's choices and needs must be integrated into an acceptable plan of care. The role of the health care team in this process includes four principal phases: planning for the baby's birth, preparing the siblings, caring for the baby, and supporting the family both at the time of the death and afterward. Specific strategies used by physicians, nurses, and child life specialists can encourage the family's full participation in the birth and death of the infant. A description of one family's experiences highlights implications for family-centered practice.

Predictive assessment of vocal efficiency (PAVE). A method for voice therapy outcome measurement

A prospective study was carried out to examine the degree to which a standard voice assessment could discriminate between the potential benefits of two different voice therapy programmes for individual patients. The study encompassed 200 dysphonia subjects who were referred for voice therapy and had completed treatment within a prescribed two-year period. A standard assessment procedure was carried out on first attendance for each patient and guidelines were used to assign patients to different treatment programmes on the basis of the assessment results. The assessment discriminated well between patients requiring voice therapy to change physiological parameters of voice usage and patients able to self adjust voice usage, and provided an objective means of measuring outcomes.

Mode of action of a lysostaphin-like bacteriolytic agent produced by Streptococcus zooepidemicus 4881

Electron microscopy of zoocin A-treated sensitive streptococcus cells revealed cytoplasmic disruption and ultimately complete rupture of the cell wall. Culture viability and optical density were shown to decrease rapidly and simultaneously in Streptococcus pyogenes FF22 but less quickly in the relatively more resistant Streptococcus mutans 10449. Zoocin A was shown to cleave hexaglycine in a colorimetric cell-free microtiter assay system, and it is concluded that the killing action of zoocin A, like that of lysostaphin, is most probably the result of direct cleavage of the peptidoglycan cross-links in the cell wall. The relationship between sensitivity to zoocin A and the peptidoglycan cross-linkage structure of Streptococcus zooepidemicus, Lactococcus spp., S. pyogenes, Streptococcus gordonii, Streptococcus oralis, S. mutans, and Streptococcus rattus has been evaluated.

Proximal promoter elements of the human zeta-globin gene confer embryonic-specific expression on a linked reporter gene in transgenic mice

We have investigated the transcriptional regulation of the human embryonic zeta-globin gene promoter. First, we examined the effect that deletion of sequences 5' to zeta-globin's CCAAT box have on zeta-promoter activity in erythroid cell lines. Deletions of sequences between -116 and -556 (cap = 0) had little effect while further deletion to -84 reduced zeta-promoter activity by only 2-3-fold in both transiently and stably transfected erythroid cells. Constructs containing 67, 84 and 556 bp of zeta-globin 5' flanking region linked to a beta-galactosidase reporter gene (lacZ) and hypersensitive site -40 (HS-40) of the human alpha-globin gene cluster were then employed for the generation of transgenic mice. LacZ expression from all constructs, including a 67 bp zeta-globin promoter, was erythroid-specific and most active between 8.5 and 10.5 days post-fertilisation. By 16.5 days gestation, lacZ expression dropped 40-100-fold. These results suggest that embryonic-specific activation of the human zeta-globin promoter is conferred by a 67 bp zeta-promoter fragment containing only a CCAAT and TATA box.

Multidrug resistance-1 (MDR1) expression and functional dye/drug efflux is highly correlated with the t(8;21) chromosomal translocation in pediatric acute myeloid leukemia

Resistance to chemotherapy is a major problem in acute myeloid leukemia (AML). An important resistance mechanism in adult AML is active drug efflux mediated by the multidrug resistance protein-1 (MDR1). To determine if MDR1 is important in childhood AML, we examined MDR1 expression and functional dye/drug efflux in 20 pediatric/adolescent AML patients; results were correlated with cytogenetics and clinical outcome. Using flow cytometry, MDR1 protein expression on the leukemic blasts was measured with the antibody MRK16, while efflux was measured by extrusion of the fluorescent dye DiO(C2)3 in the presence/absence of cyclosporin A (CsA). Six of 20 cases expressed MDR1. While all six MDR1+ cases were efflux+, three of 14 MDR1- cases also demonstrated efflux. Both MDR1 and efflux were strongly correlated with the t(8;21). All six MDR1 +/efflux+ cases and 2/3 MDR1 -/efflux+ cases had a t(8;21), while no MDR1-/efflux- cases had a t(8;21) (P < 0.0005). This correlation between MDR1, efflux, and the t(8;21) in pediatric AML was not found in 11 adult t(8;21) cases similarly studied. Although the clinical relevance of MDR1 in pediatric AML awaits larger studies, our results suggest a biologic subset of pediatric AML patients may benefit from regimens which include MDR1-reversing agents or non-MDR1 substrates.

Engineering of DNA binding proteins into site-specific cutters: reactivity of Trp repressor-1,10-phenanthroline chimeras

Trp repressor (TrpR) can be converted into a site-specific nuclease by chemical modification of the cysteine mutants TrpR D46C or TrpR E49C with 5-iodoacetamido-1,10-phenanthroline (OP). In the presence of cupric ion and 3-mercaptopropionic acid, TrpR-regulated operators are cleaved. The properties of these semisynthetic scission reagents have been compared. The E49C construct cleaves efficiently at two sites within the operator and the D46C cleaves at multiple sites. Molecular modeling indicates that the reason for the focused reactivity of E49C is that the OP is rigidly oriented in the protein-DNA complexes whereas the OP can adopt several orientations in TrpR D46C. Mutations and reaction conditions that increase the affinity of the repressor enhance the scission efficiency which approaches 100% within the acrylamide matrix. TrpR E49C-OP smoothly cleaves the trpEDCBA operator in a plasmid in a reaction dependent on the corepressor L-tryptophan. In the absence of tryptophan, non-specific cleavage of the plasmid is observed under the same conditions. Therefore, tryptophan not only directs cleavage to a specific site but also blocks it at non-specific sites. The analysis of the cleavage pattern of the trpEDCBA operator provides strong evidence for the tandem binding model in which protein-protein interactions stabilize binding on the DNA. TrpR E49C-OP should serve as the basis for the engineering of a family of highly specific semisynthetic scission reagents.

Natural assemblages of marine bacteria exhibiting high-speed motility and large accelerations

Natural communities of marine bacteria, an isolate (FMB-Bf3) from one marine community, and Escherichia coli were examined by video microscopy for the magnitude and uniformity of their speed. Natural communities formed tight microswarms that showed higher speeds (mean = 230 microns s-1) than did E. coli (15 microns s-1) or FMB-Bf3 (mean = 62 microns s-1). Outside the microswarms, the marine bacteria slowed to 45 microns s-1. Between turns, in mid run, and while travelling in straight lines, the natural-community bacteria accelerated up to 1,450 microns s-2 while the cultured bacteria showed maximum accelerations of 70 and 166 microns s-2. The frequency distribution of speed change for the marine bacteria was skewed towards a few large negative accelerations and a range of positive accelerations. The general pattern was one of relatively slow increases in speed followed by abrupt declines. The results indicate that the mechanical generation and energetic maintenance, as well as the environmental function, of bacterial motility need reappraisal. We conclude that the standard bacterial motility parameters of low and uniform speed, derived from culture-based studies, are not necessarily applicable to marine bacterial communities.

Sp1 functions in a chromatin-dependent manner to augment human alpha-globin promoter activity

The 5' flanking region of the human alpha-globin gene is highly G + C rich and contains multiple copies of the consensus sequence for the Sp1 binding site. We investigated the role of this G + C-rich region in augmenting alpha-globin promoter activity in the presence of the far-upstream alpha-globin enhancer, HS-40. We show that in transiently transfected erythroid cells, deletion of the alpha-globin G + C-rich 5' flanking region has no effect on alpha-globin promoter activity. However, upon stable integration into chromatin, deletion of this region causes a nearly 90% decrease in promoter activity compared with expression from an alpha-globin promoter retaining this region. These results suggest that the alpha-globin G + C-rich 5' flanking region augments alpha-globin promoter activity in a chromatin-dependent manner. We further show that this G + C-rich region is required for the activation of alpha-globin gene expression during erythroid differentiation. Finally, we show by both footprint analysis and functional assays that the ability of the G + C-rich region to increase alpha-globin promoter activity from a stably integrated alpha-globin gene is mediated by its multiple binding sites for the transcription factor Sp1.

A rationale for mouth care: the integration of theory with practice

Mouth care is a commonly performed nursing procedure in which the aim is to ensure that patients' mouths are cared for. However, there is evidence that unless dental plaque is removed from the tooth surfaces and the gingival margin, the mouth is in danger of becoming unhealthy and, therefore, uncared for. It appears from the dental literature that the use of a toothbrush is one of the best and most widely used tools in the Western world for removing dental plaque (Addy, Slayne & Wade 1992), other methods being ineffective, dangerous, or poorly researched (Trenter-Roth & Creason 1986). However, a review of the nursing literature indicates that toothbrushes are not the tools of choice for mouth care by nurses (Howarth 1977, Harris 1980). Thus, there appears to be a gulf between the knowledge base from the dental literature and the reality of nursing practice resulting in 'mouth care' becoming a misleading misnomer. The aim in this paper is to present a rationale for mouth care based upon the dental literature and to apply such knowledge to nursing practice, especially in intensive therapy units (ITUs), so that nurses may be in a better position to provide 'mouth care' which lives up to its name.

Inhibition of prokaryotic and eukaryotic transcription by the 2:1 2,9-dimethyl-1,10-phenanthroline-cuprous complex, a ligand specific for open complexes

The redox-stable, tetrahedral cuprous chelate of neocuproine (2,9-dimethyl-1,10-phenanthroline) binds to the single-stranded DNA formed in open complexes and is an effective inhibitor of eukaryotic and prokaryotic transcription. Despite the many kinetic and structural differences between prokaryotic and eukaryotic transcription systems, they are all similarly inhibited by neocuproine copper, suggesting that all open complexes may share a homologous structure.

Footprinting RNA-protein complexes following gel retardation assays: application to the R-17-procoat-RNA and tat--TAR interactions

RNA-protein complexes isolated following a gel retardation assay can be footprinted within the gel matrix using the chemical nuclease activities of 4,7-dimethyl-, 5,6-dimethyl-, and 3,4,7,8-tetramethyl-1,10-phenanthroline-copper. These complexes are more reactive than 1,10-phenanthroline-copper but share its reaction preference for bulges and loops. The interaction of the coat protein of R-17 with its viral RNA target and tat- and tat-derived peptides with HIV TAR RNA have been studied. In both cases, the RNA sequence opposite a 2-3 nucleotide bulge are protected. Tat-derived peptides inhibit cleavage at sites which intact tat does not protect. These results are consistent with transcription studies which have suggested that truncation of tat increases nonspecific binding.

Allergies, upper respiratory tract infections, and asthma

The aims of this study were (1) to quantify the prevalence of aeroallergen hypersensitivity in presentations for emergency treatment of asthma and (2) to determine the strength of association between viral upper respiratory tract infections (URTIs) and admission for treatment of asthma. A series of 209 asthmatic patients presenting to the Emergency Department (ED) of the Alfred Hospital over 6 months underwent skin prick testing and venipuncture for serum IgE and rye grass pollen (RGP) RAST. A case-control study of 38 asthmatic inpatients and 90 controls admitted for road trauma or endoscopy underwent nasopharyngeal aspiration for viral culture and immunofluorescence (IF). Eighty-four percent of ED asthmatic patients had one or more positive skin tests to common aeroallergens, 57% had a positive skin test, and 45% had a positive RAST to RGP. Viral cultures or IF studies were positive in 8 asthmatic patients and 2 controls. Asthmatic inpatients were 6 times more likely to have a viral URTI than were controls. It is concluded that aeroallergen hypersensitivity is present in most asthmatic patients presenting to the ED, and that there is a strong association between viral URTIs and admission for asthma.

Lymphoid specific gene expression of the adenovirus early region 3 promoter is mediated by NF-kappa B binding motifs

A primary site of infection by human adenoviruses is lymphoid cells. However, analysis of the viral control elements and the cellular factors that regulate adenoviral gene expression in lymphocytes has not been reported. The adenovirus early region 3 (ES) gene products are involved in the maintenance of viral persistence by complexing with the class I MHC antigens, thus preventing their cell surface expression with a resultant decrease in host immunologic destruction. To determine whether different cellular factors were involved in E3 regulation in lymphocytes as compared with HeLa cells, both DNA binding and transfection analysis with the E3 promoter in both cell types were performed. These studies detected two novel domains referred to as L1 and L2 with a variety of lymphoid but not HeLa extracts. Each of these domains possessed strong homology to motifs previously found to bind the cellular factor NF-kappa B. Transfections of E3 constructs linked to the chloramphenicol acetyltransferase gene revealed that mutagenesis of the distal NF-kappa B motif (L2) had minimal effects on promoter expression in HeLa cells, but resulted in dramatic decreases in expression by lymphoid cells. In contrast, mutagenesis of proximal NF-kappa B motif (L1) had minimal effects on gene expression in both HeLa cells and lymphoid cells but resulted in a small, but reproducible, increase in gene expression in lymphoid cells when coupled to the L2 mutation. Reversing the position and subsequent mutagenesis of the L1 and L2 domains indicated that the primary sequence of these motifs rather than their position in the E3 promoter was critical for regulating gene expression.(ABSTRACT TRUNCATED AT 250 WORDS)

A transdominant tat mutant that inhibits tat-induced gene expression from the human immunodeficiency virus long terminal repeat

Regulation of human immunodeficiency virus (HIV) gene expression is dependent on specific regulatory regions in the long terminal repeat. These regions include the enhancer, SP1, "TATA," and trans-activating (TAR) regions. In addition, viral regulatory proteins such as tat and rev are important in regulating HIV gene expression. The mechanism of tat activation remains the subject of investigation, but effects at both transcriptional and posttranscriptional levels seem likely. Previous mutagenesis of the tat protein revealed that the amino terminus, the cysteine-rich domain, and the basic domain were all required for complete tat activation. Mutants of other viral trans-acting regulatory proteins, including E1A, tax, and VM65, have been identified that were capable of antagonizing the activity of their corresponding wild-type proteins. We wished to determine whether mutants of the tat protein could be identified that exhibited a similar phenotype. One mutant (delta tat) that truncated the basic domain of tat resulted in a transdominant phenotype inhibiting tat-induced gene expression of the HIV long terminal repeat but not other viral promoters. This mutant exhibited its maximal phenotype in cotransfection experiments when present in an 8- to 30-fold molar excess over the wild-type tat gene. Trans-activation of the HIV long terminal repeat by delta tat was very defective at the DNA concentrations used in these experiments. RNase protection analysis indicated that this mutant decreased tat-induced steady-state mRNA levels of the HIV long terminal repeat. Second-site mutations of the delta tat gene in either the amino terminus or cysteine region eliminated the transdominant phenotype. In contrast to tat, which was localized predominantly to the nucleolus, delta tat was present in both the nucleus and cytoplasm, suggesting that it may inhibit tat function by preventing nucleolar localization. Transdominant mutants of tat may have a role in potentially inhibiting HIV gene expression.

Remitting, seronegative, symmetrical synovitis with pitting edema--13 additional cases

The case histories of 13 elderly patients (8 men/5 women) with a relatively acute onset of a severe symmetrical synovitis affecting the flexor digitorum tendon sheaths and wrist joints with pitting edema of the dorsum of both hands are described. All were persistently seronegative for IgM rheumatoid factors and all went into complete remission without relapse. Asymptomatic residual flexion contractures of the fingers and wrists were a constant feature during remission. HLA-B7 was present in 15 of a total 23 reported cases (relative risk = 4.4). This condition, with its excellent prognosis, is differentiated from rheumatoid arthritis and polymyalgia rheumatica.

Diverse soybean actin transcripts contain a large intron in the 5' untranslated leader: structural similarity to vertebrate muscle actin genes

Plant actins are encoded by complex and highly divergent multigene families. Despite the general lack of intron conservation in animal, fungal and protist actin genes, evidence is presented which indicates that higher plant actin genes have an untranslated leader exon with structural similarity to that found in vertebrate actin genes. All functional higher plant actin genes sequenced to date contain a potential intron acceptor site in the 5' untranslated region 10 to 13 nucleotides upstream of the initiator ATG. A leader specific cDNA probe hybridized to sequences over 1.0 kbp upstream from the coding region confirming the presence of an upstream exon. Primer extension of mRNA with gene-specific oligonucleotides was used to analyze the 5' untranslated exon and leader intron from four divergent soybean actin genes, SAc3, 4, 6 and 7. The 5' ends of all four mRNAs are heterogeneous. The consensus promoter elements of the SAc7 actin promoter were identified. Gene specific primer extension sequencing of actin mRNAs indicated that splicing of the 5' leader intron occurred at the predicted acceptor site in SAc6 and SAc7. The SAc6 and SAc7 5' untranslated exons are small (88-111 nt) and the leader introns are relatively large (844-1496 nt). The presence of an intron within the 5' RNA leader and an intron which splits a glycine codon at position 152 in all plant actin genes and all vertebrate muscle actin genes suggests that these structures may have been conserved due to a functional role in actin expression. The 5' regions of these two soybean actin genes contain many unusual features including (CT) repeats and long stretches of pyrimidine-rich DNA. The possible roles of the upstream exon/intron and the C + T-rich regions are discussed.

Multiple transcriptional regulatory domains in the human immunodeficiency virus type 1 long terminal repeat are involved in basal and E1A/E1B-induced promoter activity

The human immunodeficiency virus (HIV) type 1 long terminal repeat (LTR) is the site of activation of the HIV tat protein. However, additional transactivators, such as the adenovirus E1A and herpesvirus ICPO proteins, have also been shown to be capable of activating the HIV LTR. Analysis of adenovirus mutants indicated that complete transactivation of the HIV LTR was dependent on both the E1A and E1B proteins. To determine which regions of the HIV LTR were important for complete E1A/E1B activation, a variety of oligonucleotide-directed mutations in HIV transcriptional regulatory domains were assayed both in vivo and in vitro. S1 nuclease analysis of RNA prepared after transfection of these HIV constructs into HeLa cells infected with wild-type adenovirus indicated that the enhancer, SP1, TATA, and a portion of the transactivation-responsive element were each required for complete E1A/E1B-mediated activation of the HIV LTR. These same promoter elements were required for both basal and E1A/E1B-induced levels of transcription in in vitro transcription reactions performed with cellular extracts prepared from cells infected with dl434, an E1A/E1B deletion mutant, or wild-type adenovirus. No mutations were found that reduced only E1A/E1B-induced expression without proportionally reducing basal levels of transcription, suggesting that E1A/E1B-mediated induction of the HIV LTR requires multiple promoter elements which are also required for basal transcriptional levels. Unlike activation by the tat protein, there was not a rigid dependence on maintenance of the transactivation-responsive stem base pairing for E1A/E1B-mediated activation either in vivo or in vitro, indicating that activation occurs by a mechanism distinct from that of tat induction.

Functional domains required for tat-induced transcriptional activation of the HIV-1 long terminal repeat

The transcriptional regulation of the human immunodeficiency virus (HIV) type I involves the interaction of both viral and cellular proteins. The viral protein tat is important in increasing the amount of viral steady-state mRNA and may also play a role in regulating the translational efficiency of viral mRNA. To identify distinct functional domains of tat, oligonucleotide-directed mutagenesis of the tat gene was performed. Point mutations of cysteine residues in three of the four Cys-X-X-Cys sequences in the tat protein resulted in a marked decrease in transcriptional activation of the HIV long terminal repeat. Point mutations which altered the basic C-domain of the protein also resulted in decreases in transcriptional activity, as did a series of mutations that repositioned either the N or C termini of the protein. Conservative mutations of other amino acids in the cysteine-rich or basic regions and in a series of proline residues in the N terminus of the molecule resulted in minimal changes in tat activation. These results suggest that several domains of tat protein are involved in transcriptional activation with the cysteine-rich domain being required for complete activity of the tat protein.

Remitting seronegative symmetrical synovitis with pitting edema. RS3PE syndrome

Eight elderly men and two elderly women presented with symmetrical polysynovitis of acute onset involving most of their appendicular joints and flexor digitorum tendons associated with pitting edema of the dorsum of both hands and both feet. Onset of seven of the ten cases could be pinpointed almost to the hour. Rheumatoid factors were absent from serum samples in all, and no radiologically evident erosions developed. Clinical and laboratory signs of inflammation and the edema disappeared gradually in each case. Treatment consisted of aspirin or other nonsteroidal anti-inflammatory drugs. Hydroxychloroquine, 200 to 400 mg/day, was given in six and gold therapy in two cases. Painless limitation of motion of the wrists and/or fingers persisted in all, although the patients were both unaware of and unhampered by this abnormality. Six of eight cases where typing was possible were positive for HLA-B7, CW7, and DQW2 (relative risk for B7, 9.5). Three cases of this syndrome were found in a consecutive series of 52 men diagnosed as having definite "rheumatoid arthritis," and thus represent a distinctive condition with an excellent prognosis.

The use of pNJ5000 as an intermediate vector for the genetic manipulation of Agrobacterium Ti-plasmids

The use of broad-host-range plasmids derived from RP4 as intermediate vectors for the transfer of narrow-host-range recombinant plasmids from Escherichia coli to Agrobacterium tumefaciens as a preliminary to marker exchange is described. Recombinant plasmids having a ColE1 type origin were linked to the RP4 derivative. Cointegrate formation appeared to take place by RecA-independent, homologous recombination within a short piece of DNA derived from the beta-lactamase gene of Tn1/Tn3 carried by both vector components, so that it never disrupted the recombinant portion of the construction. pNJ5000 provides an unstable intermediate vector for use in marker exchange experiments, while its stable relative pNJ1020 provides a carrier for use in binary vector systems.

Prophylactic lymph node dissection in clinical stage I cutaneous malignant melanoma: results of surgical treatment in 1319 patients

A retrospective study was made of 1319 patients with cutaneous primary malignant melanoma and regional lymph nodes clinically free of disease, whose first definitive surgical treatment was either (a) wide excision of the primary lesion (WE) or (b) wide excision of the primary lesion plus a prophylactic lymph node dissection (PLND). Patients were stratified according to three dominant prognostic factors, as revealed by multifactorial analyses: sex of patient, the anatomical site and thickness of the primary lesion. Of 380 patients who underwent PLND for lymph nodes clinically free of disease, there was microscopic evidence of nodal metastases in 5 per cent. Despite this, prognosis in these patients was nearly twice as good as in those patients undergoing lymph node dissection for clinically involved nodes. Five-year survival rates for all those clinical stage I patients with lesions less than 0.8 mm thick were high irrespective of initial surgical treatment. In men with lesions of intermediate thickness (particularly 1.6-3.0 mm), survival rates for those undergoing PLND were considerably higher than for those undergoing WE. There were no survival benefits of PLND in men with lesions thicker than 3.0 mm. This was in contrast to the situation in women, where PLND was indicated for patients with the thickest lesions. This study has defined three parameters which can serve as useful practical guides for selecting alternative surgical procedures in the management of clinical stage I cutaneous malignant melanoma.