Dietary bioflavonoids induce cleavage in the MLL gene and may contribute to infant leukemia

Chromosomal translocations involving the MLL gene occur in about 80% of infant leukemia. In the search for possible agents inducing infant leukemia, we identified bioflavonoids, natural substances in food as well as in dietary supplements, that cause site-specific DNA cleavage in the MLL breakpoint cluster region (BCR) in vivo. The MLL BCR DNA cleavage was shown in primary progenitor hematopoietic cells from healthy newborns and adults as well as in cell lines; it colocalized with the MLL BCR cleavage site induced by chemotherapeutic agents, such as etoposide (VP16) and doxorubicin (Dox). Both in vivo and additional in vitro experiments demonstrated topoisomerase II (topo II) as the target of bioflavonoids similar to VP16 and Dox. Based on 20 bioflavonoids tested, we identified a common structure essential for topo II-induced DNA cleavage. Reversibility experiments demonstrated a religation of the bioflavonoid as well as the VP16-induced MLL cleavage site. Our observations support a two-stage model of cellular processing of topo II inhibitors: The first and reversible stage of topo II-induced DNA cleavage results in DNA repair, but also rarely in chromosome translocations; whereas the second, nonreversible stage leads to cell death because of an accumulation of DNA damage. These results suggest that maternal ingestion of bioflavonoids may induce MLL breaks and potentially translocations in utero leading to infant and early childhood leukemia.

Complement system of bony and cartilaginous fish

Accumulating evidence indicates that the complement system experienced a discontinuous development at an early stage of vertebrate evolution. Invertebrates such as echinoderms and ascidians, and the most primitive extant vertebrates, the cyclostomes, seem to have a primitive complement system equipped only with the alternative and lectin pathways. In contrast, cartilaginous fish and higher vertebrates seem to have a modern complement system which has two additional pathways, namely the classical and lytic pathways. Recent molecular analyses of the complement system of bony and cartilaginous fish have not only confirmed the above conclusion, but also revealed a unique characteristic of the complement system of fish, where certain key component genes are duplicated. The complement system seems to play a more pivotal role in body defence in fish, whose adaptive immunity is considered to be at a relatively undeveloped state.

Evaluation of a hip joint simulator

To evaluate the functioning of the Durham hip joint wear simulator, the wear rates of ultra high molecular weight polyethylene (UHMWPE) and polytetrafluoroethylene (PTFE) acetabular cups articulating against 22 mm diameter cobalt-chromium-molybdenum (CoCrMo) femoral heads were studied. A wear test was conducted in a lubricant of distilled water at 37 degrees C for a duration of 4.8 million cycles. The average penetration rate for the CoCrMo femoral heads against UHMWPE acetabular cups was 0.03 mm/10(6) cycles, while penetration rate for PTFE cups was some twenty times greater. These results are of a similar order of magnitude to other simulator studies in distilled water and are in a similar ratio to clinical data.

A comparison between gravimetric and volumetric techniques of wear measurement of UHMWPE acetabular cups against zirconia and cobalt-chromium-molybdenum femoral heads in a hip simulator

Five cobalt-chromium-molybdenum (CoCrMo) and five zirconia femoral head components have been wear tested against 28 mm diameter ultra high molecular weight polyethylene (UHMWPE) acetabular cups for 5 million cycles in the Durham hip joint wear simulator using bovine serum as a lubricant. Wear measurements used gravimetric and volumetric techniques and no statistically significant difference was found between the measurement methods. The wear rates of the acetabular cups against both femoral heads are presented for both measurement methods. The UHMWPE acetabular cups showed a statistically significant higher linear wear rate for the first 2 million cycles than the lower linear wear rate from 2 million cycles to the end of the test, against both femoral head materials. Over the full duration of the wear test, the wear rates of acetabular cups articulating against zirconia femoral heads were lower than against CoCrMo femoral heads. The wear rates up to 2 million cycles and from 2 to 5 million cycles for both femoral head materials were consistent with other studies.

A multifunctional ATP-binding cassette transporter system from Vibrio cholerae transports vibriobactin and enterobactin

Vibrio cholerae uses the catechol siderophore vibriobactin for iron transport under iron-limiting conditions. We have identified genes for vibriobactin transport and mapped them within the vibriobactin biosynthetic gene cluster. Within this genetic region we have identified four genes, viuP, viuD, viuG and viuC, whose protein products have homology to the periplasmic binding protein, the two integral cytoplasmic membrane proteins, and the ATPase component, respectively, of other iron transport systems. The amino-terminal region of ViuP has homology to a lipoprotein signal sequence, and ViuP could be labeled with [(3)H]palmitic acid. This suggests that ViuP is a membrane lipoprotein. The ViuPDGC system transports both vibriobactin and enterobactin in Escherichia coli. In the same assay, the E. coli enterobactin transport system, FepBDGC, allowed the utilization of enterobactin but not vibriobactin. Although the entire viuPDGC system could complement mutations in fepB, fepD, fepG, or fepC, only viuC was able to independently complement the corresponding fep mutation. This indicates that these proteins usually function as a complex. V. cholerae strains carrying a mutation in viuP or in viuG were constructed by marker exchange. These mutations reduced, but did not completely eliminate, vibriobactin utilization. This suggests that V. cholerae contains genes in addition to viuPDGC that function in the transport of catechol siderophores.

Latanoprost 0.005% and anterior segment uveitis

PURPOSE

To evaluate the association of latanoprost with anterior chamber uveitis in glaucoma patients.

METHODS

We retrospectively reviewed 527 charts in latanoprost treated patients with: no prior uveitis (Group 1); prior uveitis but were inactive at the time of the study (Group 2); and active uveitis (Group 3).

RESULTS

In Group 1 five (1.0%) of 505 patients developed uveitis after beginning latanoprost. The uveitis was trace to 1+ cell in severity and delayed in onset 99.8+/-73.9 days In Group 2 three of 13 (23.1%) patients developed delayed uveitis (trace to 1+ cell). In Group 3 zero of nine (0%) patients had worsened inflammation and the intraocular pressure remained unchanged (22.8+/-7.8 mmHg to 22.0+/-7.3 mmHg) after beginning latanoprost (p=0.38).

CONCLUSION

In patients without a prior history a mild delayed uveitis with latanoprost treatment may develop rarely. In patients with a uveitis history, a mild delayed exacerbation potentially may occur and the intraocular pressure may not be decreased in active uveitis.

Analysis of pressure achieved by various materials used for pressure dressings

BACKGROUND

To minimize the risk of complications, pressure dressings are frequently applied to wounds. The actual pressures yielded by different dressing materials and application techniques have not been documented.

OBJECTIVE

To measure and compare pressures produced using various types of dressing tapes with and without a gauze roll.

METHODS

An infant blood pressure cuff was adapted for use in a pressure dressing model. Investigators independently applied four strips of each of five different types of tape to the cuff when it was located in three settings: a hard inanimate surface, a subject's distal volar forearm, and the subject's forehead.

RESULTS

Foam and plastic tapes produced more pressure under a simple dressing than three other commonly used tapes. Higher, more consistent pressures were achieved on the forearm than the forehead. Adding a gauze roll to the dressing consistently increased the pressure.

CONCLUSION

The experimental model demonstrated substantial differences in pressures yielded by various pressure dressing materials.

A review of major factors contributing to errors in human hair association by microscopy

Forensic hair examiners using traditional microscopic comparison techniques cannot state with certainty, except in extremely rare cases, that a found hair originated from a particular individual. They also cannot provide a statistical likelihood that a hair came from a certain individual and not another. There is no data available regarding the frequency of a specific microscopic hair characteristic (i.e., microtype) or trait in a particular population. Microtype is a term we use to describe certain internal characteristics and features expressed when observing hairs with unpolarized transmitted light. Courts seem to be sympathetic to lawyer's concerns that there are no accepted probability standards for human hair identification. Under Daubert, microscopic hair analysis testimony (or other scientific testimony) is allowed if the technique can be shown to have testability, peer review, general acceptance, and a known error rate. As with other forensic disciplines, laboratory error rate determination for a specific hair comparison case is not possible. Polymerase chain reaction (PCR)-based typing of hair roots offer hair examiners an opportunity to begin cataloging data with regard to microscopic hair association error rates. This is certainly a realistic manner in which to ascertain which hair microtypes and case circumstances repeatedly cause difficulty in association. Two cases are presented in which PCR typing revealed an incorrect inclusion in one and an incorrect exclusion in another. This paper does not suggest that such limited observations define a rate of occurrence. These cases illustrate evidentiary conditions or case circumstances which may potentially contribute to microscopic hair association errors. Issues discussed in this review paper address the potential questions an expert witness may expect in a Daubert hair analysis admissibility hearing.

Acyclovir is phosphorylated by the human cytomegalovirus UL97 protein

Acyclovir (ACV) has shown efficacy in the prophylactic suppression of human cytomegalovirus (HCMV) reactivation in immunocompromised renal transplant patients without the toxicity associated with ganciclovir (GCV). The HCMV UL97 gene product, a protein kinase, is responsible for the phosphorylation of GCV in HCMV-infected cells. This report provides evidence for the phosphorylation of ACV by UL97. Anabolism studies with the HCMV wild-type strain AD169 and with recombinant mutants derived from marker transfer experiments performed by using mutant UL97 DNA from both clinical isolates and a laboratory-derived strain resistant to GCV showed that mutations in the UL97 gene cripple the ability of recombinant virus-infected cells to anabolize both GCV and ACV. These mutant UL97 recombinant viruses were less susceptible to both GCV and ACV than was the wild-type strain. A recombinant herpes simplex virus type 1 strain, in which the thymidine kinase gene is deleted and the UL13 gene is replaced with the HCMV UL97 gene, was able to induce the phosphorylation of ACV in infected cells. Finally, purified UL97 phosphorylated both GCV and ACV to their monophosphates. Our results indicate that UL97 promotes the selective activity of ACV against HCMV.

Is mammography of value in women with disseminated cancer of unknown origin?

Mammography is often requested to try to identify occult primary breast carcinoma in women with metastatic cancer of unknown primary site. This study aimed to investigate whether mammography is of use in these patients in identifying the breast as the origin of the metastatic disease. Thirty-one women with a working diagnosis of metastatic cancer underwent mammography in an attempt to determine the primary site. None of these women had a palpable breast mass. The site of presentation, pathological type of tumour, site of origin, and benefit of mammography and mammography-provoked biopsy were clarified for each patient. The patients were also followed up to determine survival. The commonest sites of presentation were lung (45%), lymph nodes (19%) and abdomen (16%). The primary sites of these cancers were identified with confidence in 27 patients (87%). The commonest known primary tumour sites were lung (45%), breast (16%) and ovary (16%). Abnormal mammograms were detected in four patients (13%), but three of these did not have breast cancer. In one, the site of origin remained indeterminate, as either breast or lung. Five (16%) had a confident diagnosis of breast carcinoma; all of these women had normal mammograms. We conclude that mammography in women presenting with metastatic disease from an unknown primary site is unhelpful and is not recommended. Furthermore, we could not demonstrate its value in women presenting with axillary lymphadenopathy.

The use of latanoprost 0.005% once daily to simplify medical therapy in patients with primary open-angle glaucoma or ocular hypertension

PURPOSE

To evaluate the use of latanoprost 0.005% given once daily to simplify a patient's glaucoma medical regimen.

METHODS

We reviewed 527 charts of which we included 61 patients (61 eyes) with either ocular hypertension or primary open-angle glaucoma who were prescribed latanoprost for the purpose of simplifying their glaucoma medical regimen. The successful substitution of latanoprost was defined as a reduction in the number of dosages given daily with the maintenance of intraocular pressure for at least three months no higher than 2 mmHg from the previous medical regimen.

RESULTS

This study showed that 43 of 61 patients (70.4%) had latanoprost substituted allowing for fewer dosages per day. Following the substitution the intraocular pressure in the success group fell from 22.5+/-5.9 mmHg to 18.3+/-3.8 mmHg (p<0.001) over an average follow-up of 6.6+/-1.9 months. The total number of dosages per day in the success group fell from 4.8+/-2.4 to 1.7+/-1.3 at exit (p<0.001). Twenty-two patients had one medicine, 14 patients two, and seven patients three medicines discontinued after latanoprost was added. Reasons for failure after the substitution were ineffectiveness of latanoprost (n=11) or an adverse event (n=7). No trends in the number or types of medicines at baseline discontinued were observed in the success or failure groups.

CONCLUSION

This study shows that latanoprost 0.005% once daily can be substituted for one or more medicines in the majority of ocular hypertension and primary open-angle glaucoma patients to simplify the medical regimen.

Stimulation of strontium accumulation in linoleate-enriched Saccharomyces cerevisiae is a result of reduced Sr2+ efflux

The influence of modified plasma membrane fatty acid composition on cellular strontium accumulation in Saccharomyces cerevisiae was investigated. Growth of S. cerevisiae in the presence of 1 mM linoleate (18:2) (which results in 18:2 incorporation to approximately 70% of total cellular and plasma membrane fatty acids, with no effect on growth rate) yielded cells that accumulated Sr2+ intracellularly at approximately twice the rate of S. cerevisiae grown without a fatty acid supplement. This effect was evident over a wide range of external Sr2+ concentrations (25 microM to 5 mM) and increased with the extent of cellular 18:2 incorporation. Stimulation of Sr2+ accumulation was not evident following enrichment of S. cerevisiae with either palmitoleate (16:1), linolenate (18:3) (n-3 and n-6 isomers), or eicosadienoate (20:2) (n-6 and n-9 isomers). Competition experiments revealed that Ca2+- and Mg2+-induced inhibition of Sr2+ accumulation did not differ between unsupplemented and 18:2-supplemented cells. Treatment with trifluoperazine (TFP) (which can act as a calmodulin antagonist and Ca2+-ATPase inhibitor), at a low concentration that precluded nonspecific K+ efflux, increased intracellular Sr2+ accumulation by approximately 3.6- and 1.4-fold in unsupplemented and 18:2-supplemented cells, respectively. Thus, TFP abolished the enhanced Sr2+ accumulation ability of 18:2-supplemented cells. Moreover, the rate of Sr2+ release from Sr2+-loaded fatty acid-unsupplemented cells was found to be at least twice as great as that from Sr2+-loaded 18:2-enriched cells. The influence of enrichment with other fatty acids on Sr2+ efflux was variable. The results reveal an enhanced Sr2+ accumulation ability of S. cerevisiae following 18:2-enrichment, which is attributed to diminished Sr2+ efflux activity in these cells.

Laparoscopic antireflux surgery--It's a wrap!

The surgical management of gastroesophageal reflux disease has been simplified by the availability of minimally invasive techniques to treat this condition. The indications and selection of patients remain the same as for open surgery and initial results with laparoscopic antireflux surgery show long-term results equal to, or better than open procedure. These procedures are technically demanding requiring surgeons skilled in advanced laparoscopy. The evaluation of patients, selection of patients for surgery, surgical techniques and anticipated outcomes are discussed.

The use of latanoprost 0.005% once daily and its effect on intraocular pressure as primary or adjunctive therapy

The purpose of this study was to evaluate differences in efficacy and safety of latanoprost as monotherapy compared to adjunctive therapy in primary open-angle glaucoma. We reviewed records of 527 patients who were treated with latanoprost as mono- or adjunctive therapy to reduce the intraocular pressure. Each patient was treated at least three months unless they were discontinued due to an adverse event or lack of efficacy. In the monotherapy group (n=49) baseline intraocular pressure of 23.6+/-5.2 mm Hg fell to 18.4+/-4.3 mm Hg after 4.4+/-2.0 months of follow-up; in the adjunctive therapy group (n=39) baseline intraocular pressure of 21.8+/-5.7 mm Hg fell to 16.7+/-4.6 mm Hg following 4.3+/-1.8 months of therapy which was a similar change from baseline for both groups (P > 0.9). No differences were noted in the class or number of medicines to which latanoprost could be added including: beta-blockers, alpha-agonists and topical carbonic anhydrase inhibitors. The reasons for failure with monotherapy were mostly adverse events (10/15 patients) and with adjunctive therapy lack of efficacy (14/16 patients). Latanoprost is similarly effective as monotherapy and as an adjunctive agent in reducing the intraocular pressure. Latanoprost can be added successfully to a variety of classes of glaucoma medicines used commonly as adjunctive therapy.

Health promotion versus disease and care: failure to establish "blissful clarity" in British nurse education and practice

An evaluation which involved documentary analysis, observation and interviews with teachers, students and nurses in four educational institutions, revealed that the interpretation and implementation of a philosophy of health in nursing in the UK has been variable. A small but influential group of teachers saw health as the basis for the curriculum and the way forward for nursing. The new Project 2000 health-based curriculum led some participants to reassess their conception of nursing, but disease and care of the sick remained uppermost. Trained hospital nurses in particular continued to view nursing as primarily concerned with disease treatment. The care model associated with 'New Nursing', rooted in communication and interpersonal relationships, was also apparent particularly among pre- and post-registration students. Health was operationalised as both health education and health promotion ranging from individualised information giving and disease prevention to more participatory forms based on equity and empowerment. Participants' responses to the introduction of health in the curriculum were categorised in one of four ways: pessimism, partisanship, fanschen (to turn over) or marketisation. Their response depended on whether they viewed health as the central nursing philosophy rather than disease or care. On the basis of our findings we propose that these responses give rise to four policy choices for nurses at an individual and group level.

From home to hospital: Parallels in birthing and dying in twentieth-century Canada

This article highlights the striking parallels in the history of birthing and dying as they moved from home to hospital in Canada in the twentieth century. It shows that deaths, like birth, has been hidden in hospitals only since mid-century. It demonstrates that the availability of paid and unpaid female caregivers was a key factor affecting the shifts in location of death, much as it was for birth. Thus, women have been the major consumers and caregivers of health services at both ends of the life cycle.

Paraesophageal herniation as a complication following laparoscopic antireflux surgery

Paraesophageal herniation of the stomach is a rare complication following laparoscopic Nissen fundoplication. We retrospectively reviewed our experience with 720 patients undergoing laparoscopic Nissen fundoplications. Seven patients were found to have postoperative paraesophageal hernias requiring reoperation. The clinical presentation, diagnostic workup, operative treatment, and outcome were evaluated. There were no deaths or procedure-related complications. Clinical presentation was recurrent dysphagia in four, nonspecific abdominal symptoms in one, and acute abdomen in one. One additional patient was asymptomatic. Preoperatively the correct diagnosis was able to be confirmed in four of six patients by barium esophagogram. Four patients underwent successful laparoscopic repair. Two patients had a thoracotomy including one conversion from laparoscopy to thoracotomy. One patient had a lap-arotomy to reduce an intrathoracic gastric volvulus. At a mean follow-up of 2.5 months no patient had further complications. Paraesophageal herniation is a rare complication following laparoscopic Nissen fundoplication and a definitive diagnosis is often difficult to establish. Early dysphagia after surgery should alert the surgeon to this complication. Redo laparoscopic surgery is feasible but an open procedure may be necessary.

The influence of education and personality on risk propensity in nurse managers

The current healthcare environment is demanding innovation. Nurse managers are positioned strategically to creatively change and innovate the patient care delivery process, if they are willing to take risks. The authors discuss a study that tests whether a nurse manager's education, years of experience, and personality are related to their propensity to take risks in administrative decision making. Results of the study indicate that nurse managers who achieved at least a bachelors degree, had higher autonomy orientations, and had lower control orientations were more likely to choose higher risk options in nursing administrative decisions. The authors found that self-esteem and years of experience were not related to nurse manager risk propensity.

Vasoactive intestinal polypeptide secreting islet cell tumors: a 15-year experience and review of the literature

BACKGROUND

Vasoactive intestinal polypeptide (VIP)-secreting tumors of the pancreas represent a rare subtype of pancreatic islet cell tumors with an estimated incidence of 0.2 to 0.5 per million per year. We provide data on a relatively large series of patients with VIP-secreting tumors and review current literature regarding this specific entity.

METHODS

A retrospective review was performed of all patients with VIP-secreting tumors of the pancreas treated from 1977 to 1992 at our institution. Presenting signs, symptoms, mode of diagnosis, extent of disease, surgical resectability, tumor size, treatments, hormone levels, and survival were assessed.

RESULTS

Eighteen patients were identified, 9 male and 9 female. Ages ranged from 23 to 74 years (mean 51 years). Secretory diarrhea was the most common symptom, occurring in 16 of 18 patients (89%). The most common tumor location was the tail of the pancreas (9 patients). Fourteen patients (78%) had liver metastasis at diagnosis. Curative resections were attempted in only 5 patients (28%). The mean survival was 3.6 years with the longest disease-free survival being 15 years and longest overall survival 15 years.

CONCLUSIONS

VIP-secreting tumors are extremely rare entities and usually metastatic at the time of diagnosis. Despite advanced disease, these patients can have extended survival.

Shark complement: an assessment

The classical (CCP) and alternative (ACP) pathways of complement activation have been established for the nurse shark (Ginglymostoma cirratum). The isolation of a cDNA clone encoding a mannan-binding protein-associated serine protease (MASP)-1-like protein from the Japanese dogfish (Triakis scyllia) suggests the presence of a lectin pathway. The CCP consists of six functionally distinct components: C1n, C2n, C3n, C4n, C8n and C9n, and is activated by immune complexes in the presence of Ca++ and Mg++ ions. The ACP is antibody independent, requiring Mg++ ions and a heat-labile 90 kDa factor B-like protein for activity. Proteins considered homologues of C1q, C3 and C4 (C2n) of the mammalian complement system have been isolated from nurse shark serum. Shark C1q is composed of at least two chain types each showing 50% identity to human C1q chains A and B. Partial sequence of the globular domain of one of the chains shows it to be C1q-like rather than like mannan-binding protein. N-terminal amino acid sequences of the alpha and beta chain of shark C3 and C4 molecules show significant identity with corresponding human C3 and C4 chains. A sequence representing shark C4 gamma chain, shows little similarity to human C4 gamma chain. The terminal shark components C8n and C9n are functional analogues of mammalian C8 and C9. Anaphylatoxin activity has been demonstrated in activated shark serum, and porcine C5a desArg induces shark leucocyte chemotaxis. The deduced amino acid sequence of a partial C3 cDNA clone from the nurse shark shows 50%, 30% and 24% homology with the corresponding region of mammalian C3, C4 and alpha 2-macroglobulin. Deduced amino acid sequence data from partial Bf/C2 cDNA clones, two from the nurse shark and one from the Japanese dogfish, suggest that at least one species of elasmobranch has two distinct Bf/C2 genes.

Patient certification through mutual problem lists

OBJECTIVE

To determine whether retired military personnel and spouses are cognizant of the patient's complete list of medical problems.

METHODS

Receiving help from their spouses or other personal care givers, 12 patients listed their health problems from memory plus from a page-by-page review of their permanent medical records. The personal physician produced his own lists and combined them with the patient-generated lists. After mutual review, these combined lists were accepted as the mutual problem lists. Other professionals in the clinic also audited the same patients' charts.

RESULTS

Twelve patients identified an average of 4.58 problems, the physician identified an average of 7.75 problems, and the other professionals identified an average of 6.54 problems.

CONCLUSION

This lack of agreement has implications for patient education and certification as full collaborators in primary care.

Organization of the simian hemorrhagic fever virus genome and identification of the sgRNA junction sequences

SHFV is a member of the Arteriviridae family. Viruses within this family encode eight open reading frames (ORFs), two of which are translated from the full-length genome RNA. The remaining six ORFs are translated from a nested set of six or seven 3' co-terminal, subgenomic RNAs (sgRNAs). We have cloned and sequenced approximately 6000 nucleotides (nt) from the 3' end of the SHFV genome. Eleven ORFs, numbered ORFs 1a, 1b, 2a, 2b, 3, 4, 5, 6, 7, 8, and 9, were identified, three more than the other arteriviruses. The characteristics of the peptides encoded by ORFs 2a through 9 were determined from their computer-generated amino acid sequences. We also amplified the junction sequences from each of the SHFV subgenomic RNAs (sgRNAs) using RT-PCR analysis. Eight separate junction sequences were found which suggests that SHFV produces eight sgRNAs during replication. ORFs 2a and 2b appear to be encoded on the same sgRNA implying that RNA 2 is polycistronic. Sequence analysis identified the conserved SHFV junction sequence as 5'-(U/C)(C/U)N(U/C)(U/C)(A/C/G)AC(C/U)-3'. Since SHFV encodes additional ORFs and produces additional sgRNAs during replication, these data suggest that SHFV may be more complex than the other arteriviruses.