Perforated appendicitis presenting with ileo-caecal ulceration and mechanical intestinal obstruction

A 30-year-old lady presented with a 6-month history of recurrent partial intestinal obstruction associated with intermittent fever, anorexia and weight loss. Barium meal follow-through and colonoscopic evaluation suggested ulceration of the ileum and caecum with small bowel obstruction. Histology of the lesions showed marked acute and chronic inflammation consistent with ulceration and granulation tissue. Abdominal CT revealed circumferential thickening of the ascending colon, caecum and terminal ileum with extraluminal air pockets. Surgical exploration revealed a large conglomerate mass involving the terminal ileum, caecum and ascending colon. Histopathology of the resected specimen revealed perforated appendix with nonspecific ulceration of the surrounding bowel. She recovered completely after surgery and did not suffer from gastrointestinal symptoms in the 14 months of follow-up.

Amoebae-resisting bacteria in drinking water: risk assessment and management

Free-living amoebae have been detected in a large number of man-made water systems, including drinking water distribution systems. Some of these amoebae can host amoebae-resisting bacteria, and thus act potentially as reservoirs and vehicles for a number of pathogens. The objectives of this study were to characterize the amoebae and amoebae-resisting bacteria present in different raw waters used for drinking water production, and to assess the efficiency of different treatments applied for drinking water production in removing or inactivating these amoebae. The preliminary results of this study confirm the presence of amoebae and amoebae-resisting bacteria in raw waters used for drinking water production. Due to their capacity to encyst, most of these amoebae are extremely resistant to disinfection processes. In these conditions, preventing the dissemination of these micro-organisms through drinking water will mainly require their physical removal by clarification and filtration processes. The particular hazard that amoebae-resisting bacteria represent in drinking water production should be taken into account in any risk assessment conducted in the framework of a water safety plan, and control strategies based on physical removal rather than disinfection should be adopted where necessary.

Relationship between mycobacteria and amoebae: ecological and epidemiological concerns

Since the discovery that Legionella pneumophila can survive and grow within free-living amoebae, there has been an increasing number of microbial species shown to have similar relationships. These include many bacterial species, fungi, other protozoa (e.g. Cryptosporidium) and viruses. Among bacteria, mycobacteria are of particular importance because of their role in human and animal infections. This review will consider the progress made in understanding the relationships between mycobacteria and amoebae, and their consequences in terms of ecology and epidemiology.

A versatile strategy to fabricate hydrogel–silver nanocomposites and investigation of their antimicrobial activity

In this study, hydrogel-silver nanocomposites have been synthesized by a unique methodology, which involves formation of silver nanoparticles within swollen poly (acrylamide-co-acrylic acid) hydrogels. The formation of silver nanoparticles was confirmed by transmission electron microscopy (TEM) and surface plasmon resonance (SPR) which was obtained at 406 nm. The TEM of hydrogel-silver nanocomposites showed almost uniform distribution of nanoparticles throughout the gel networks. Most of the particles, as revealed from the particle-size distribution curve, were 24-30 nm in size. The X-ray diffraction pattern also confirmed the face centered cubic (fcc) structure of silver nanoparticles. The nanocomposites demonstrated excellent antibacterial effects on Escherichia coli (E. coli). The antibacterial activity depended on size of the nanocomposites, amount of silver nanoparticles, and amount of monomer acid present within the hydrogel-silver nanocomposites. It was also found that immersion of plain hydrogel in 20 mg/30 ml AgNO(3) solution yielded nanocomparticle-hydrogel composites with optimum bactericidal activity.

A role for tissue transglutaminase in alpha-gliadin peptide cytotoxicity

In coeliac disease, gliadin peptides p56-88, p57-68 and p31-49 have been demonstrated to be involved in the pathogenic damage of the small intestine via their immunogenicity or toxicity to epithelial cells. To try to understand the mechanism of their toxicity, we investigated the effect of synthetic peptides (p31-49, p56-88, p57-68, p69-82) and of their deamidated analogues on Caco2 and FHs 74 Int cell toxicity and tissue tranglutaminase activity. Apoptosis, necrosis and cell viability were assessed by flow cytometry, and peptide deamidation was determined indirectly by measuring its capacity to inhibit tTG activity. The results showed that p56-88 and p57-68 reduced cell growth and concomitantly inhibited tTG activity in both cell types. This effect was abolished when Caco2 cells were treated with antibodies to tTG. Deamidated peptide p57-68 (E(65)) lost practically all of its inhibitory effect on cell growth and on tTG activity. Cellular toxicity was also observed with p31-49, which was not a substrate for tTG. p69-82 was not cytotoxic but became so when glutamine 72 was substituted by glutamic acid. These findings provide evidence for the existence of three types of toxicity among gliadin peptides: (i) peptides that are intrinsically toxic and are not substrates of tTG; (ii) peptides that are non-toxic but become so when they act as substrates of tTG; and (iii) peptides that are non-toxic and are not substrates of tTG but become so when deamidated. A mechanism other than that involving tTG could be responsible for the deamidation of glutamine residues of gliadin in the intestinal tract.

Association of cathepsin B gene polymorphisms with tropical calcific pancreatitis

BACKGROUND AND AIMS

Tropical calcific pancreatitis (TCP) is a type of chronic pancreatitis unique to countries in the tropics. Mutations in pancreatic secretory trypsin inhibitor (SPINK1) rather than cationic trypsinogen (PRSS1) explain the disease in only 50% of TCP patients. As cathepsin B (CTSB) is known to activate cationic trypsinogen, we attempted to understand the role of CTSB mutations in TCP. Evidence of epistatic interaction was investigated with the previously associated N34S SPINK1 allele, a variant considered to be a modifier rather than a true susceptibility allele.

SUBJECTS AND METHODS

We sequenced the coding region of CTSB gene in 51 TCP patients and 25 controls and further genotyped 89 patients and 130 controls from the same cohort for Leu26Val, C595T, T663C, and Ser53Gly polymorphisms. The positive findings observed in the earlier cohort were re-examined in an ethnically matched replication cohort comprising 166 patients and 175 controls. Appropriate statistical analyses were performed and Bonferroni correction for multiple testing was applied.

RESULTS

We found a statistically significant association of the Val26 allele at Leu26Val polymorphism with an odds ratio (OR) of 2.15 (95% confidence interval (CI) 1.60-2.90 (p = 0.009)), after Bonferroni correction (corrected p value = 0.025). This significant association of Leu26Val with TCP was replicated in another cohort (OR 2.10 (95% CI 1.56-2.84); p = 0.013). Val26 allele also showed significantly higher frequency in N34S positive and N34S negative patients than in controls (p = 0.019 and 0.013, respectively). We also found significant differences in the mutant allele frequencies at Ser53Gly and C595T single nucleotide polymorphisms between N34S positive patients and controls (p = 0.008 and 0.001, respectively). Although haplotype analysis did not complement the results of allelic association, it did uncover a unique haplotype protective for TCP (p = 0.0035).

CONCLUSION

Our study suggests for the first time that CTSB polymorphisms are associated with TCP. As PRSS1 mutations are absent in TCP and the N34S SPINK1 mutation is proposed to play a modifier role, these variants may be critical as a trigger for cationic trypsinogen activation.

Antibacterial activity of cefquinome against equine bacterial pathogens

Cefquinome is known for its use as an antibacterial drug in cattle and pigs. The objective of this study was to evaluate the antibacterial activity of cefquinome against equine pathogenic bacteria. The minimum inhibitory concentration (MIC) of cefquinome was determined for a total of 205 strains, which had recently been isolated in Europe from diseased horses (respiratory infection, foal septicaemia). The bactericidal activity was tested against 19 strains using the time killing method. The post-antibiotic effect (PAE) and post-antibiotic sub-MIC effect (PA SME) were determined against 12 strains. Cefquinome showed high activity against Actinobacillus equuli and streptococci (MIC(90) of 0.016 and 0.032microg/mL), Enterobacteriaceae (MIC(90)=0.125microg/mL) and staphylococci (MIC(90)=0.5microg/mL). The activity was limited against Rhodococcus spp. and Pseudomonas spp. Cefquinome was shown to be a time dependent bactericidal antibiotic against the target pathogens, killing occurring at a concentration close to the MIC. A PAE of 0.5-10h was calculated against streptococci whereas no PAE was observed for Escherichia coli. A longer PA SME was determined for streptococci (3.3 to >24h with a killing effect) and E. coli (0.5-13.9h). Cefquinome was shown to have a broad spectrum of activity which covers many equine pathogens.

The prognostic determinants of gastric cancer treatment outcome in Omani Arab patients

BACKGROUND

Gastric cancer is the most common cancer in Oman and a leading cause of cancer death. The variation in survival rates between countries and ethnic groups has been attributed to early detection policies, differences in clinicopathological features, treatment approaches, and biological characteristics. There were no previous reports on gastric cancer from Oman and very few studies on Asian Arabs.

AIM

To evaluate the impact of clinicopathological and treatment variables on the survival prospects of Omani Arab patients diagnosed with gastric cancer.

METHODS

The medical records of 339 Omani Arab patients diagnosed with invasive gastric adenocarcinoma during the period 1993-2004 were retrospectively reviewed. The relative importance of clinicopathological features and surgical and medical treatments were assessed using univariate and multivariate analyses.

RESULTS

Most patients had distal ulcerating-type gastric cancer and presented at advanced stages. The median survival time for the entire cohort was 12 months (95% CI 9.7-14.4) with a 5-year overall survival rate of 16.7%. On univariate analysis of 237 patients who underwent surgical resection, the following positive prognostic factors emerged as significant: early overall TNM stage, early T stage, negative lymph nodes, tumor size <5 cm, ulcerating macroscopic appearance, and curative surgical attempt. The independent prognostic factors on multivariate analysis were T stage and lymph node involvement.

CONCLUSION

The overall T and N stages are the most important determining factor for survival in Omani Arab patients. More efforts need to be made for the early detection of gastric cancer in developing countries such as Oman, while continuing to employ the standard surgical and medical treatments.

Comparison of disinfectants for biofilm, protozoa and Legionella control

The aim of this study was to compare the efficiency of different disinfectants applicable to Legionella control in domestic water systems. A domestic water supply simulation unit that allowed simulation of real-world conditions was developed for this purpose. The system, consisting of seven identical rigs, was used to compare treatment efficiency under equivalent conditions of system design, materials, hydraulics, water quality, temperature and initial contamination. During the study, each of six loops received continuous application of one of the following disinfectants: chlorine, electro-chlorination, chlorine dioxide, monochloramine, ozone, or copper/silver. The seventh loop was used as a control and remained untreated. Performance evaluation of these disinfectants was based on their ability to reduce not only Legionella, but also protozoa and biofilms, which contribute to the establishment and dissemination of these bacteria in water systems, and their resistance to treatments. Regarding these criteria, chlorine dioxide and chlorine (as bleach or obtained by electro-chlorination) were the most effective treatments in this study. However, in comparison with chlorine, chlorine dioxide showed a longer residual activity in the system, which constituted an advantage in the perspective of an application to extensive pipework systems.

Myeloablative conditioning is well tolerated by older patients receiving T-cell-depleted grafts

Older age has been linked to increased transplant-related mortality from graft-versus-host disease (GvHD). Depletion of T cells from stem cell grafts seems to protect from complications of GvHD particularly in older patients. After myeloablative conditioning, patients with haematological malignancies received allogeneic grafts from HLA identical siblings. For GvHD prophylaxis, PBPC grafts were treated ex vivo with anti-CD52, and therapeutic doses of cyclosporin until day +90. Survival of patients younger or older than the population age median was analysed. In all, 62 consecutive patients with a median age of 42.5 years were studied. Death was procedure related in 17% and from relapse of malignancy in five. At a median, follow-up is 662 (7-2316) days, 74% survive disease free. The rate of haematopoietic recovery and treatment-related mortality was similar in both groups. A total of 73% of 30 individuals in the younger group and 75% (P=0.8) in the older cohort survive at a median follow-up of 444 and 806 days (P=0.4). GvHD occurred in 13% and was the only adverse factor for survival (P<0.04). Myeloablative conditioning is well tolerated up to the age of 59 in patients receiving T-cell-depleted grafts. This information is useful to more precisely select patients who would benefit most from reduced intensity conditioning schedules.

The prognostic significance of p53, p27 kip1, p21 waf1, HER-2/neu, and Ki67 proteins expression in gastric cancer: a clinicopathological and immunohistochemical study of 121 Arab patients

BACKGROUND

The variability of prognosis within a pathological stage of gastric cancer (GC) at presentation, underscores the need for specific biological markers to identify subgroups of patients with aggressive course for intensive treatment. To our knowledge, this is the first study from an Arab population reporting on the relationship of p53, p27 kip1, p21 waf1, HER-2/neu, and Ki67 expression, and clinicopathological features and their prognostic significance.

METHODS

Formalin-fixed paraffin-embedded tumors were studied by immunohistochemistry, using monoclonal antibodies to p53, p27 kip1, p21 waf1, HER-2/neu, and Ki67. The results were correlated with clinicopathological features and survival.

RESULTS

M:F = 80:41; median age = 60 years; stage III and IV = 71%; and median follow-up = 34.4 months. Positive expression rates of p53, p27 kip1, p21 waf1, Ki67, and HER-2/neu were 54%, 40%, 8.3%, 70%, and 12% respectively. p53 expression correlated with age <60 years (P = 0.03), tumor size >5 cm (P = 0.01), p27 kip1 and Ki67 expression (P = 0.0001), and HER-2/neu (P = 0.04). p21 waf1 correlated inversely with T-stage (P = 0.008) and Her-2/neu expression correlated with histological grade (P = 0.04) and T-stage (P = 0.008). Univariate analysis showed that p53 overexpression (P = 0.01), fungating and infiltrative macroscopic appearance (P = 0.02), size >5 cm (P = 0.0001), lymph node metastasis (P = 0.0001), p T3 and T4 disease (P = 0.01), and overall stage III and IV (P = 0.0001) disease were adverse prognostic factors. Patients with tumor profiles p53 (-)/p27 (+) had better survival than those with p53 (+)/p27 kip1 (-)(P = 0.02). On multivariate analysis by Cox regression model, the expression of p53 (P = 0.03) and lymph node involvement (P = 0.01) were significant adverse prognostic factors for overall survival.

CONCLUSIONS

The expression of p53 in Arab patients with GC correlates with aggressive tumor characteristics and is an independent prognostic factor. The combined analysis of p53 and p27 kip1 is of added prognostic value.

Is preoperative core biopsy accurate in determining the hormone receptor status in women with invasive breast cancer?

Background

The objective of this study was to determine the concordance rate between core needle biopsy (CNB) and surgical excision of invasive breast cancer regarding the oestrogen receptor (ER) and Progesterone receptor (PgR) status as determined by Immunohistochemistry (IHC).

Methods

Hormone receptor status was established using IHC (using quickscore system 0–8) on preoperative CNB and subsequent surgical excision in 93 patients with invasive breast cancer. Results were compared taking into account tumour's size, grade, and patient's age.

Results

The ER concordance rate between CNB and surgical excisions was 95%. The PgR concordance rate was 89%. This shows that CNB has a sensitivity of 97% for ER and 95% for PgR.

There is a positive correlation of ER and PgR between CNB and surgical excision (p < 0.000001). There was no significant difference in the number of core biopsies between concordant and discordant cases.

Conclusion

Preoperative core biopsy is highly sensitive for the IHC detection of ER and PgR in invasive breast cancer. The concordance rate is higher for ER than PgR, which could be due to the fact that ER is more homogeneously distributed.

Amoebae in domestic water systems: resistance to disinfection treatments and implication in Legionella persistence

AIMS

Monitoring of microbial changes during and after application of various disinfection treatments in a model domestic water system.

METHODS AND RESULTS

A pilot-scale domestic water system consisting of seven galvanized steel re-circulation loops and copper dead legs was constructed. Culture techniques, confocal laser scanning microscopy after fluorescent in situ hybridization and viability staining with the BacLight LIVE/DEAD kit were used for planktonic and biofilm flora monitoring. Before starting the treatments, the system was highly contaminated with Legionella pneumophila and biofilm populations mainly consisted of beta-proteobacteria. In the water and the biofilm of the loops, continuous application of chlorine dioxide (0.5 mg l(-1)), or chlorine (2.5 mg l(-1)) were very effective in reducing the microbial flora, including L. pneumophila. Heterotrophic bacteria, although strongly reduced, were still detectable after ozone application (0.5 mg l(-1)), whereas with monochloramine (0.5 mg l(-1)) and copper-silver ionization (0.8/0.02 mg l(-1)), the contamination remained significantly higher. Monochloramine and copper-silver did not remove the biofilm. During copper-silver application, Legionella re-growth was observed. Only chlorine dioxide led to detectable effects in the dead leg. Amoebae could not be eliminated, and after interrupting the treatments, L. pneumophila quickly recovered their initial levels, in all cases.

CONCLUSIONS

Chlorine dioxide, applied as a continuous treatment, was identified in this study as the most efficient for controlling L. pneumophila in a domestic water system. Chlorine dioxide showed a longer residual activity, leading to improved performance in the dead leg. Amoebae resisted to all the treatments applied and probably acted as reservoirs for L. pneumophila, allowing a quick re-colonization of the system once the treatments were interrupted.

SIGNIFICANCE AND IMPACT OF THE STUDY

Control of microbial contamination requires maintenance of a constant disinfectant residual throughout the water system. Treatment strategies targeting free-living amoebae should lead to improved control of L. pneumophila. Such treatment strategies still have to be investigated.

The clinical importance of axillary lymphadenopathy detected on screening mammography: revisited

AIM

The aim of this study was to re-evaluate our protocol for the management of isolated axillary lymphadenopathy (ALP) on mammographic screening.

METHODS

In a retrospective review of 200,716 women screened at the South West London Breast Screening Service (SWLBSS) over 7 years, 72 women with ALP with an otherwise normal mammogram were identified. Thirteen patients were not recalled, nine of who had a known underlying diagnosis and the remainder had longstanding unchanged mammograms. Fifty-nine patients were recalled for further clinical assessment and investigations, including ultrasound, further mammographic views, fine-needle aspiration cytology (FNAC), blood tests and a chest radiograph. Those with a definite diagnosis were referred for appropriate management and those with benign reactive cytology on FNAC reviewed at 6 weeks with subsequent referral for excision of persisting abnormal nodes.

RESULTS

The ultimate diagnosis was benign in 45 cases: 26 benign reactive changes, 11 arthritides, five with dermatological and viral conditions and three with tuberculosis. Malignancy was diagnosed in 13 cases: four with metastatic breast carcinoma and nine with lymphoma/leukaemia. The total number of newly diagnosed malignancies was 20% of women recalled. Another 5% of patients had active tuberculosis. Of the 22 patients with benign reactive cytology, one had significant pathology on excision biopsy: tuberculosis. Over 95% of the results from excision biopsy in these patients did not alter management.

CONCLUSION

In the majority of patients, the FNAC results were representative of the final excision pathology. The present study suggests that excision biopsy could be omitted for those patients whose FNAC and culture are negative.

Optical Characterization of Eu3+Ions in CdSe Nanocrystal Containing Silica Glass

Silica glass samples containing CdSe/Eu3+ ions were prepared by sol-gel route. Size distribution and optical band gap of the nanoparticles were calculated from absorption spectrum. It is observed that the presence of CdSe nanocrystallites enhances the fluorescence of europium in silica glass. The phonon sideband spectrum associated with the excitation transition 7F0-5D2 is used to analyze the electron-phonon coupling and nonradiative deexcitiation of the rare earth ions in the glass host, The observed fluorescence enhancement is discussed on the basis of phonon assisted energy transfer from electron-hole recombination of the CdSe nanocrystallites to the rare earth ion and multiphonon relaxation.

Radiotherapy-based conditioning is effective immunosuppression for patients undergoing transplantation with T-cell depleted stem cell grafts for severe aplasia

BACKGROUND

We studied the outcome of individuals with aplastic anemia conditioned with a radiation-containing regimen followed by an infusion of stem cell grafts that had been depleted of lymphocytes with CAMPATH-1H (antiCD52; humanised).

METHODS

The conditioning regime consisted of fractionated (f) TBI 8 Gy followed by f total nodal irradiation (TNI) 6 Gy. In addition, patients received CY 60 mg/kg on 2 consecutive days. Cytokine-mobilized peripheral blood grafts from HLA-identical siblings were T-cell depleted with CAMPATH-1H 'in the bag'. CsA was commenced on day -1 and continued until day +90.

RESULTS

Seventeen heavily transfused patients with aplastic anemia, median age 18 years (range 14-56 years), were studied. The median time from diagnosis to transplantation was 172 days (range 34-443 days). The median CD34(+) cell number infused was 3.47 x 10(6)/kg (range 1.03-18.4 x 10(6)/kg). All patients engrafted. Recovery was fast and patients reached 0.5 x 10(9)/L polymorphs by median day 11 (range 9-17 days). Toxicity from the conditioning included grade 4 hematologic toxicity in all patients. Another major toxicity was gastrointestinal mucosal damage, which exceeded grade 2 in two instances. One patient developed thrombotic thrombocytopenic purpura, which responded to substitution of CsA with tacrolimus and plasmapheresis. Another patient, who had normal blood counts, died of infection on day 241. Chimerism studies at 6 months post-transplantation confirmed the donor origin of hematopoiesis in all seven patients tested. None of the patients developed acute or chronic GvHD. There was no delayed graft failure and 94% of patients had survived disease free at a median of 1303.5 days (range 216-2615 days) from graft infusion.

DISCUSSION

In this cohort of multiply transfused patients, the radiation-containing schedules described in this study led to universal engraftment with limited toxicity despite T-cell depletion. No patient developed GvHD or late graft failure. Lower doses of radiation-containing conditioning should be explored further.

[Hospital nurses' perception of public health]

The objective of this work was to study hospital nurses' perceptions of public health based on a pedagogical exercise. A qualitative study, lead by students of a training institute for nursing care (IFSI), was conducted using semi-directed interviews of hospital nurses from different departments of a provincial hospital. The main results show that for one-third of the nurses interviewed, the hospital is not a setting for public health practice. In terms of their definition of public health, it is closely linked to the concept of prevention, with primarily individual approaches. This definition is very close to the public health activities that they conduct at the hospital and which are centred on information and disease prevention, on education related to pathologies and the relationship between the provision of care and listening to the patients and their families. Few nurses place their public health activities within the scope of the areas of hospital cleanliness, the welcoming of the patients, the organisation of services, and the improvement of the quality of care. The potential tracks which have emerged from this work lead to the need for the strengthening of training in patient education, in the hospital's work networking with external partners, and in better development of public health activities undertaken in the hospital setting.

Increasing dose intensity of anthracycline antibiotics improves outcome in patients with acute myelogenous leukemia

To understand the effect of dose concentration in the overall survival of AML, we conducted a study on the efficacy and toxicity of a drug combination where the dose of daunorubicin was intensified. For this analysis, the outcome of patients entered into two consecutive prospective trials was compared. Inclusion criteria in both arms were identical and consisted of primary AML in adults. Treatment protocol for Cape Town Regimen 4 (CTR-IV) comprised of cytarabine infusion (100 mg/m(2)) and etoposide (100 mg/m(2)), injection daily for 7 days in combination with daunorubicin (45 mg/m(2)) on days 1, 2, and 3. Patients achieving remission were given two further courses of the same chemotherapy and received allogeneic or autologous transplantation. CTR-V was a similar treatment program, except that daunorubicin was escalated on days 1, 2, and 3 to 75 mg/m(2) during induction and to 60 mg/m(2) during a single consolidation. Patients were also offered stem cell transplantation. Between 1990 and 1997, 78 patients (median age 33; range 13-67 years) fulfilled entry criteria and received CTR-IV. From 1998 onwards, 35 patients (median age 36; range 15-66 years) were prospectively enlisted into the CTR-V trial. The patient population in CTR-V had fewer Caucasian individuals (P = 0.02) and had significantly lower presentation hemoglobin (P = 0.0002). Following initiation of induction chemotherapy, 40 patients failed to respond. Among these, 10 patients demised before day 28. Another 30 (25/69 CTR-IV and 5/32 in CTR-V groups; P = 0.01) had leukemia that was resistant to chemotherapy, and all died. Remission was achieved in 59% of patients treated with CTR-IV and 77% of those receiving CTR-V (P = 0.03). CR occurred with a single course in 64% versus 88% (P = 0.02), respectively. There were no differences in the toxicity profile between these two combinations. Disease recurred in 50% and 28% (P = 0.07) of patients. For the 113 individuals, median follow up is 254 (range 19-4,451) and 304 (12-1,702; P = 0.03) days. Survival is 23% and 40%, respectively, favoring patients treated with CTR-V (log rank; P = 0.03). Cox regression analysis showed that treatment group (P < 0.001), FAB type, hemoglobin level, and platelet count were independent factors for response to chemotherapy. Older age and not undergoing myeloablative therapy were the only adverse factors for survival. We conclude that increase in the treatment dose of daunorubicin in patients with AML led to a higher remission rate, particularly with a single course of chemotherapy and had an equivalent toxicity profile. This therapeutic modification is also likely to result in substantial reduction in patient stay in hospital and in the overall expenditure.

Campath-1 Abs ‘in the bag’ for hematological malignancies: the Cape Town experience

BACKGROUND

We examined the strategy of T-cell depletion of HLA-identical sibling grafts for the prevention of GvHD, as well as disease control and overall survival.

PATIENTS AND METHODS

The myeloablative conditioning was radiation based. The source of stem cells was BM in 62, and cytokine-mobilized PBPC in 68 patients. GvHD prophylaxis was by ex vivo incubation of the stem-cell concentrates with Campath-1G (anti-CD52; n=76) or Campath-1H (n=54).

RESULTS

Patients receiving PBPC grafts were older (median 38.5) than those undergoing BMT (median 31; P=0.002). More patients in the PBPC group developed chronic GvHD (p<0.01). While no post-transplant GvHD prophylaxis was given to BMT recipients, prednisone 30 mg daily was prescribed to 12 and CYA for 90 days to a further 32 patients who had received PBPC grafts. Median follow-up was 1055 (range 28-4867) days. Although there was no difference in the survival between patients who received BMT or PBPC, death was from disease recurrence in 16 and nine (p=0.03; chi(2) test) subjects, respectively. Multivariate analysis showed that outcome was particularly favorable in those who were given<20 mg Campath-1 (survival: 28/39 versus 12/29; P=0.01), and in the subgroup of 30 patients who received Campath-1H and post-transplantation CYA.

DISCUSSION

In patients receiving BMT, Campath-1 Abs effectively prevent GvHD. For those treated with PBPC grafts, the combination of T-cell depletion and post-transplantation CYA is equally effective, without an obvious increase in disease recurrence.

Intensified myeloablative therapy and autologous stem-cell transplantation for patients with AML: single center experience

BACKGROUND

Thirty-seven consecutive individuals in CR of AML received intensified conditioning and autologous stem-cell transplantation.

METHODS

For those receiving PBSC (n = 28), mobilization protocol was with cyclophosphamide 60 mg/kg followed by G-CSF injection at 5-10 microg/kg; stem cells were harvested by large volume apheresis (6-8 blood volumes) and then cryopreserved. Ablative therapy consisted of fractionated TBI (total 12 Gy), followed by four fractions (1.5 Gy each) of total nodal irradiation (TNI), and CY 120 mg/kg under mesna cover.

RESULTS

For individuals transplanted in CR 1 (n = 31) the median time from diagnosis to grafting was 167 (range 92 - 212) days. Patients transplanted with PBSC received high number of CFU-GM x 10(4)/kg (P < 0.01), a difference that was associated with a significantly shorter platelet recovery. While there was no early transplant-associated mortality, in 10 patients death was caused by recurrence of the disease. The median survival is 1746 (range 105-4467) days and 26 (70%) survive disease free, at a median 2207 (range 698-4467) days from transplantation. Multivariate analysis showed that survival of patients with AML-M3, receiving higher CFU-GM (P = 0.04) and without morphological dysplasia (P = 0.01) was longest.

DISCUSSION

For patients in remission of AML, transplantation with PBPC appears to be an effective form of intensification, particularly when TBI + TNI (delivering a total of 18 Gy to the axial skeleton) were used as conditioning.

In vitro studies on the effect of physical cross-linking on the biological performance of aliphatic poly(urethane urea) for blood contact applications

The effect of physical cross-linking in candidate cycloaliphatic and hydrophobic poly(urethane urea) (4,4'-methylenebis(cyclohexylisocyanate), H(12)MDI/hydroxy-terminated polybutadiene, HTPBD/hexamethylenediamine, HDA) and poly(ether urethane urea)s (H(12)MDI/HTPBD-PTMG/HDA) on the in vitro calcification and blood-material interaction was studied. All the candidate poly(urethane urea)s and poly(ether urethane urea)s elicit acceptable hemolytic activity, cytocompatibility, calcification, and blood compatibility in vitro. The studies on blood-material interaction reveal that the present poly(urethane urea)s are superior to polystyrene microtiter plates which were used for the studies on blood-material interaction. The present investigation reveals the influence of physical cross-link density on biological interaction differently with poly(urethane urea) and poly(ether urethane urea)s. The higher the physical cross-link density in the poly(urethane urea)s, the higher the calcification and consumption of WBC in whole blood. On the other hand, the higher the physical cross-link density in the poly(ether urethane urea)s, the lesser the calcification and consumption of WBC in whole blood. However a reverse of the above trend has been observed with the platelet consumption in the poly(urethane urea)s and poly(ether urethane urea)s.

Coping strategies of people with HIV/AIDS in negative health care experiences

The purpose of the study was to gain insight into coping strategies of people with HIV/AIDS (PWHAs) in Taiwan who had negative health care experiences. This study used a phenomenological approach. Participants were 14 PWHAs with an average age of 35 years who had known their positive HIV status for an average of 24.9 months. Two coping strategies used to deal with negative health care experiences included, 'don't make a big fuss about it', and 'building defenses and finding alternatives'. Cultural aspects of PWHAs' coping strategies are discussed as they distinguish Chinese from western culture.

Polypropylene fumarate/phloroglucinol triglycidyl methacrylate blend for use as partially biodegradable orthopaedic cement

Polypropylene fumarate/phloroglucinol triglycidyl methacrylate oligomeric blend-based bone cement was studied. Higher the percentage of phloroglucinol triglycidyl methacrylate, lesser the setting time. An optimum setting time could be arrived with 50:50 blend composition of the two oligomers. Composite cement of 50:50 blend prepared with hydroxyapatite granules of particle size 125 microm binds bovine rib bones. The tensile strength of this adhesive bond was found to be 1.11 kPa. The thermal studies suggest the onset of cross-linking reaction in the cured blend if the blend is heated. The absence of softening endotherm in the cured blend shows the thermosetting-like amorphous nature of blend system, which may restrict the changes in creep properties. The in vitro biodegradation studies reveal possible association of calcium ions with negatively charged units of degrading polymer chain resulting in slow down of degradation. Relatively slow degradation was observed in Ringer's solution. The study reveals the potential use of polypropylene fumarate/phloroglucinol triglycidyl methacrylate as partially degradable polymeric cement for orthopaedic applications.

Studies on the effect of virtual crosslinking on the hydrolytic stability of novel aliphatic polyurethane ureas for blood contact applications

The effect of virtual crosslinking on the hydrolytic stability of completely aliphatic novel poly(urethane ureas), HFL9-PU1 (hard-segment content 57.5%) and HFL13-PU2 (hard-segment content 67.9%) based on 4,4'-methylene bis(cyclohexyl isocyanate) (H(12)MDI)-hydroxy-terminated polybutadiene-1,6-hexamethylene diamine, was studied. Fourier transform infrared-attenuated total reflectance and wide-angle X-ray diffraction studies revealed hydrogen-bonding interaction and microphase separation and formation of crystallites by short- and long-range ordering in hard-segment domains. Three-dimensional networks from hydrogen bonding in the present polymers lead to virtually crosslinking and insolubility. These polymers were noncytotoxic to L929 fibroblast cells. The hemolytic potential is below the accepted limit. The studies on in vitro biostability in Ringer's solution, phosphate buffered saline, and papain enzyme revealed no weight loss. The infrared spectral studies revealed changes in the surface, especially on HFL9-PU1 aged in Ringer's solution and phosphate buffered saline, and no changes when aged in papain. The marginal changes noticed in tensile properties were attributed to the changes in degree of hydrogen bonding and associated rearrangement of molecular structure in the bulk. The results revealed that the lesser the crosslinking in virgin polymer, the higher the crosslinking in aged polymer and vice versa. Increased crosslinking during aging provided increased tensile properties in the aged polymer over the virgin polymer and vice versa. For comparison, an aliphatic polyetherurethane urea (HFL16-PU3) was also synthesized using poly(oxy tetra methylene glycol) in addition to the above reactants. Though both HFL9-PU1 and HFL16-PU3 contained the same hard-segment content, the aged sample of the latter showed decreased tensile properties with increased crosslinking during aging in contrast to the former. This was attributed to less microphase separation in the virgin HFL16-PU3 polymer.

Vitamin D receptor gene polymorphisms are associated with breast cancer risk in a UK Caucasian population

There is increasing evidence that vitamin D can protect against breast cancer. The actions of vitamin D are mediated via the vitamin D receptor (VDR). We have investigated whether polymorphisms in the VDR gene are associated with altered breast cancer risk in a UK Caucasian population. We recruited 241 women following a negative screening mammogram and 181 women with known breast cancer. The VDR polymorphism Bsm I, an intronic 3' gene variant, was significantly associated with increased breast cancer risk: odds ratio bb vs BB genotype = 2.32 (95% CI, 1.23-4.39). The Bsm I polymorphism was in linkage disequilibrium with a candidate translational control site, the variable length poly (A) sequence in the 3' untranslated region. Thus, the 'L' poly (A) variant was also associated with a similar breast cancer risk. A 5' VDR gene variant, Fok I, was not associated with breast cancer risk. Further investigations into the mechanisms of interactions of the VDR with other environmental and/or genetic influences to alter breast cancer risk may lead to a new understanding of the role of vitamin D in the control of cellular and developmental pathways.

Effect of Li+ upon the Mg2+-dependent activation of recombinant Gialpha1

Although lithium salts have been used in the treatment and prophylaxis of manic-depressive or bipolar patients for 50 years, the mechanism of the pharmacologic action of Li+ is unknown. Based on activity studies of inhibitory and stimulatory guanine-binding (G) proteins in rat cortical membranes, it was proposed that Li+ inhibition of G-proteins may account for its pharmacologic action. We used the purified alpha subunit of the recombinant inhibitory G-protein, rGialpha1, and found that Li+ at therapeutic levels significantly inhibited the formation of the GDP.AlF4-.rGialpha1 complex. Because our studies were conducted with a purified, metal-reconstituted G-protein rather than with cell membrane suspensions, our Li+ inhibition results lend additional support to the G-protein hypothesis for Li+ action.

Stroke patterns in cardio-embolic infarction in a population-based study

The study demonstrates that clinical-radiological causes and outcome of cardio-embolic infarcts in a population-based study correspond to a well-identified stroke pattern. Cardio-embolic infarcts was diagnosed in 882 cases (37.9%) of 2,330 consecutive first-ever stroke patients included in a prospective population-based stroke registry over a 14-year period (1985-1997). Thirty-three criteria out of 98 were introduced into a monovariate analysis and the significant variable were introduced into a multivariate analysis to identify significant criteria to define stroke patterns in cardio-embolic infarction. Cardiac sources of embolus included atrial arrhythmia, valvular heart disease (19%), and cardiac failure (18%). Patients with cardio-embolic infarction showed a significantly higher rate of female predominance (p < 0.001), history of ischemic heart disease (p < 0.001), acute stroke onset (p < 0.05), headache (p < 0.05), previous treatment by anti-platelets and anti-K-vitamin (p < 0.001), Wernicke aphasia (p < 0.001), severe deficit (p < 0.001) and death (p < 0.001). After a logistic procedure, female gender and ischemic heart disease were the two independent risk factors associated with cardio-embolic stroke. Cardio-embolic stroke is a specific subtype of stroke with its own clinical, radiological, etiological and prognostic characteristics. In the acute stage, it is necessary to identify quickly this type of stroke because of severe prognosis and appropriate treatment.

Analysis of the expression of cell cycle regulators in Ewing cell lines: EWS-FLI-1 modulates p57KIP2and c-Myc expression

Ewing tumour is characterized by specific chromosome translocations which fuse EWS to a subset of genes encoding ETS transcription factors, most frequently FLI-1. We report the analysis of the expression of various cell cycle regulators both in Ewing tumour derived cell lines and in different cellular models with either inducible or constitutive EWS-FLI-1 cDNA expression. In Ewing cell lines, cyclin D1, CDK4, Rb, p27KIP1 and c-Myc were consistently highly expressed whereas p57KIP2, p15INK4B and p14ARF demonstrated undetectable or low expression levels. The amount of p16INK4A, p21CIP1, p18INKAC and CDK6 was variable from one cell line to the other. The inducible expression of EWS-FLI-1 led to a strong upregulation of c-Myc and a considerable downregulation of p57KIP2. Other proteins did not show evident modification. High c-Myc and very low p57KIP2 expression levels were also observed in neuroblastoma NGP cells constitutively expressing EWS-FLI-1 as compared to parental cells. Analysis of the p57KIP2 promoter indicated that EWS-FLI-1 downregulates, possibly through an indirect mechanism, the transcription of this gene. Finally, we show that ectopic expression of p57KIP2 in Ewing cells blocks proliferation through a complete G1 arrest. These results suggest that the modulation of p57(KIP2) expression by EWS-FLI-1 is a fundamental step in Ewing tumorigenesis.

Dissociation of infectivity and pathogenicity in Borrelia burgdorferi

Clonal Borrelia burgdorferi N40 (cN40) passaged 75 times in vitro (N40-75) infects mice but does not cause disease. N40-75 passaged 45 times further in vitro (N40-120) was no longer infectious and lacked genes encoded on linear plasmids 38 and 28-1, among other differences. These data suggest that B. burgdorferi cN40, N40-75, and N40-120 have distinct phenotypes that can be used to dissect the genetic elements responsible for pathogenicity and infectivity.

Coinfection with Borrelia burgdorferi and the agent of human granulocytic ehrlichiosis alters murine immune responses, pathogen burden, and severity of Lyme arthritis

Lyme disease and human granulocytic ehrlichiosis (HGE) are tick-borne illnesses caused by Borrelia burgdorferi and the agent of HGE, respectively. We investigated the influence of dual infection with B. burgdorferi and the HGE agent on the course of murine Lyme arthritis and granulocytic ehrlichiosis. Coinfection resulted in increased levels of both pathogens and more severe Lyme arthritis compared with those in mice infected with B. burgdorferi alone. The increase in bacterial burden during dual infection was associated with enhanced acquisition of both organisms by larval ticks that were allowed to engorge upon infected mice. Coinfection also resulted in diminished interleukin-12 (IL-12), gamma interferon (IFN-gamma), and tumor necrosis factor alpha levels and elevated IL-6 levels in murine sera. During dual infection, IFN-gamma receptor expression on macrophages was also reduced, implying a decrease in phagocyte activation. These results suggest that coinfection of mice with B. burgdorferi and the HGE agent modulates host immune responses, resulting in increased bacterial burden, Lyme arthritis, and pathogen transmission to the vector.

Studies on poly(propylene fumarate-co-ethylene glycol) based bone cement

Poly(propylene fumarate-co-ethylene glycol) random (PPF-1) and block (PPF-2) copolymer oligomers were prepared. Comparing the setting characteristics of PPF-1 and PPF-2 with comonomer n-vinyl pyrrolidone (n-VP) and swelling characteristics of cured PPF-1 and PPF-2, lower setting temperature and setting time was observed with the former leading to higher swelling coefficient and lower cross link density in the cured PPF-1. Due to the high swelling coefficient and low setting exothermic temperature associated with PPF-1, the bone cement was prepared from PPF-1, n-VP and hydroxyapatite (HAP). The in vitro degradation studies reveal lesser weight loss and deformation of PPF-1/n-VP/HAP based cured resin in Ringer's solution and phosphate buffered saline in comparison with that of PPF-1/n-VP cured resin. Though the bone cement composite has adequate mechanical properties with HAP, the compressive strength and modulus of the composite aged in Ringer's solution and PBS reduced appreciably which is due to extensive hydration and plasticization by the PEG unit. However, the bone-binding and bond strength of the bone cement determined as the load for separation of bones was found to be similar to that of fast setting calcium phosphate-atelocollagen (5%) bone cement. The bone cement PPF-1/n-VP/HAP could be used as scaffold for correcting the bone defects.