A prospective, randomized assessment of a novel, local antibiotic releasing platform for the prevention of superficial and deep surgical site infections.

BACKGROUND: Despite significant advances in infection control guidelines and practices, surgical site infections (SSIs) remain a substantial cause of morbidity, prolonged hospitalization, and mortality among patients having both elective and emergent surgeries. D-PLEX100 is a novel, antibiotic-eluting polymer-lipid matrix that supplies a high, local concentration of doxycycline for the prevention of superficial and deep SSIs. The aim of our study was to evaluate the safety and efficacy of D-PLEX in addition to standard of care (SOC) in preventing superficial and deep surgical site infections for patients undergoing elective colorectal surgery. METHODS: From October 10, 2018 to October 6, 2019, as part of a Phase 2 clinical trial, we randomly assigned 202 patients who had scheduled elective colorectal surgery to receive either standard of care SSI prophylaxis or D-PLEX100 in addition to standard of care. The primary objective was to assess the efficacy of D-PLEX100 in superficial and deep SSI reduction, as measured by the incidence of SSIs within 30 days, as adjudicated by both an individual assessor and a three-person endpoint adjudication committee, all of whom were blinded to study-group assignments. Safety was assessed by the stratification and incidence of treatment-emergent adverse events. RESULTS: One hundred and seventy-nine patients were evaluated in the per protocol population, 88 in the intervention arm [51 males, 37 females, median age (64.0 range: 19-92) years] and 91 in the control arm [57 males, 34 females, median age 64.5 (range: 21-88) years]. The SSI rate within 30 day post-index surgery revealed a 64% relative risk reduction in SSI rate in the D-PLEX100 plus standard of care (SOC) group [n = 7/88 (8%)] vs SOC alone [n = 20/91 (22%)]; p = 0.0115. There was no significant difference in treatment-emergent adverse events. CONCLUSIONS: D-PLEX100 application leads to a statistically significant reduction in superficial and deep surgical site infections in this colorectal clinical model without any associated increase in adverse events.

Immunoglobulin kappa gene rearrangements between the kappa deleting element and Jkappa recombination signal sequences in acute lymphoblastic leukemia and normal hematopoiesis.

The kappa deleting element (kappaDE) located 24 kb downstream of the Ckappa gene segment mediates the deletion of Ckappa and the Jkappa-Ckappa Intron enhancer, which results in allelic exclusion of the immunoglobulin kappa light chain locus. We here report that the kappaDE can recombine to each recombination signal sequence (RSS) flankappaing Jkappa1 to Jkappa5 in normal hematopoiesis. Moreover, usage of the JkappaRSS-kappaDE junctional sequence allows the detection of minimal residual disease in acute lymphoblastic leukemia.

T cell receptor Ddelta2Ddelta3 rearrangement: a suitable allele-specific marker for the detection of minimal residual disease in childhood acute lymphoblastic leukemia.

The applicability of T cell receptor (TCR) Ddelta2Ddelta3 junctional regions for the detection of minimal residual disease (MRD) was examined in childhood acute lymphoblastic leukemia (ALL). Southern blot analysis showed a Ddelta2Ddelta3 rearrangement in 22 of 172 (13%) precursor-B ALL. No Ddelta2Ddelta3 rearrangement was identified in 29 T-ALL cases. Three patients exhibited Ddelta2Ddelta3 recombinations in both alleles. Sequence analysis of Ddelta2Ddelta3 junctions revealed extensive diversity due to the random insertion and deletion of nucleotides at the joining site. PCR analysis utilizing allele-specific probes or oligonucleotides generated on the basis of Ddelta2Ddelta3 junctional sequences reached a sufficient sensitivity of 10(-4) to 10(-5) in the majority of cases. In four of 25 (16%) rearranged alleles, however, the 5' heptamer-nonamer recombination signal sequence (RSS) of the Ddelta2 segment had recombined directly to the 3' heptamer-nonamer RSS of the Ddelta3 segment thus generating a so-called signal junction. Respective heptamer-heptamer junctions are not suited to design allele-specific oligonucleotides for the detection of MRD because of their limited diversity and hence specificity.

Insufficient stocking of poisoning antidotes in hospital pharmacies.

OBJECTIVE: To determine whether antidotes for poisoning and overdose are available in hospitals that provide emergency department care. DESIGN: Written survey of hospital pharmacy directors, each of whom reported the amount currently in stock of 8 different antidotes: antivenin (Crotalidae) polyvalent, cyanide kit, deferoxamine mesylate, digoxin immune Fab, ethanol, naloxone hydrochloride, pralidoxime chloride, and pyridoxine hydrochloride. PARTICIPANTS: Pharmacy directors of all hospitals with emergency departments in Colorado, Montana, and Nevada. MAIN OUTCOME MEASURES: Proportions of hospitals with insufficient stocking of each antidote, defined as complete lack of the antidote or an amount inadequate to initiate treatment of 1 seriously poisoned 70-kg patient. RESULTS: Questionnaires were mailed to 137 hospital pharmacy directors and 108 (79%) responded. Only 1 (0.9%) of the 108 hospitals stocked all 8 antidotes in adequate amounts. The rate of insufficient stocking for individual antidotes ranged from 2% (for naloxone) to 98% (for digoxin immune Fab). In a multiple regression analysis, smaller hospital size and lack of a formal review of antidote stocking were independent predictors of the number of antidotes stocked insufficiently. CONCLUSIONS: Insufficient stocking of antidotes is a widespread problem in Colorado, Montana, and Nevada. Although these states are served by a certified regional poison center, potentially lifesaving antidotes are frequently not available when and where they might be needed to treat a single poisoned patient.

Management of alimentary tract duplication in children.

Duplication of the alimentary tract is rare but potentially dangerous. Five of 72 children with alimentary tract duplication treated between 1973 and 1992 died from postoperative complications; a further ten required more than one operation. Ileal duplications were the commonest, occurring in 16 patients (22 per cent). Thoracoabdominal duplications were the most complicated and responsible for much of the overall morbidity and mortality. Surgical complications were related to the size and location of the duplication, communication with the gastrointestinal tract or vertebral canal, presence of heterotopic gastric mucosa and involvement of mesenteric vessels. Complete excision of the duplication should be possible in most cases.

Slow cytotoxicity of the polysaccharide levan on tumor cells in vitro.

Previous studies have shown that 1 h preincubation with levan caused a sharp decrease in tumorigenicity of tumor cells, although cell viability was not affected. In the present study, the possibility that levan might change the sensitivity of Lewis lung carcinoma cells to the host immune system and that levan might cause delayed damage were tested. Cell morphology, DNA synthesis, cell multiplication and viability as well as osmotic fragility were followed during several days in culture. Levan was found not to affect cell immunogenicity. The polysaccharide destroyed tumor cells by a rather peculiar mechanism: after a seemingly normal or even enhanced growth in culture during 3-5 days, cells suddenly burst. During the apparently normal growth, several morphological changes were observed: cell volume increased, cytoplasm swelled by apparent water uptake and some cells contained two or more nuclei. Levan-treated cells were found to be more susceptible to osmotic shock than non-treated cells. The reason for the sudden cell death could be a gradual increase in volume, up to a point which is no more compatible with membrane integrity, resulting in cell lysis.

Different effects of the polysaccharide levan on the oncogenicity of cells of two variants of Lewis lung carcinoma.

A marked difference in sensitivity to the direct effect of the polysaccharide levan on tumour cells was observed between two variants of malignancy of Lewis lung carcinoma: cells of the more malignant variant (3LL-M) were much more sensitive to the drug than those of the less malignant tumour (3LL). A gradual decrease in tumorigenicity following preincubation with increasing levan concentrations was observed with both variants, but statistically significant inhibition was observed at lower levan concentrations with 3LL-M than with 3LL.

Different biological behavior of AKR lymphoma cells from primary and metastatic tumors.

AKR lymphoma cells derived from primary s.c. tumors (PT) and cells from their metastases (MT) were inoculated into recipient mice in order to compare their malignant behavior. A higher malignant potential of MT compared to PT cells was found. The results support the hypothesis that metastasis is a process of selection of cells possessing a potential to metastasize, which preexist in the primary tumor. In the model used, both the selection of 'variants' of malignancy and the assay of malignancy were as close as possible to natural tumor progression.

Different stages of tumor development are unequally affected by pretreatment of tumor cells with a polysaccharide.

Pretreatment with the polysaccharide levan of Lewis lung carcinoma and AKR lymphoma cells affected unequally different stages of tumor development. While levan pretreatment sharply reduced the evolution of tumors from subcutaneously inoculated cells, no such inhibition was observed with pretreated cells inoculated intravenously. Since levan is known to affect the cell membrane, it is concluded that different cell membrane properties may be involved in the various stages of tumor progression.

Direct antitumor effect of the polysaccharide levan in mice: effects of drug concentration and time and temperature of incubation.

In vitro treatment of Lewis lung carcinoma cells with the polysaccharide levan was shown previously to reduce the oncogenicity of these cells by acting on the cell membrane. In the present study the direct effect of levan on the tumorigenicity of Lewis lung carcinoma in C57BL male mice was tested at different doses and intervals and temperatures of incubation. A dose-dependent decrease in tumorigenicity was observed: Doses of 0.5, 1, and 2 mg levan/2 X 10(5) cells/0.2 ml reduced tumor incidence by 30, 50, and 70%, respectively. Some degree of inhibition was observed even with a dose of 0.004 mg. The inhibitory effect was rapid; 5 minutes of incubation resulted in the same reduction in oncogenicity as 60 minutes. Inhibition at 0 degree C was as effective as inhibition at 37 degrees C. The lack of temperature effect indicates that enzymatic activity probably is not involved. The data presented here, together with previous data, suggest that levan induces a physical, rather than a chemical, change in the affected tumor cells. The polysaccharide appears to be loosely, noncovalently bound to the cell membrane.

Change from inhibition to stimulation by levan of AKR lymphoma following serial transfers.

A progressive increase in malignancy following serial passages of AKR lymphoma is often accompanied by loss in sensitivity to the antitumor agent, levan. In further transfers, stimulation of tumor growth, instead of inhibition, is sometimes observed. It is proposed that the shift from inhibition to stimulation of tumor growth by the immunomodulator levan may be due to a change during tumor progression in the sensitivity of the tumor cells to the reported dual effect of macrophages, inhibitory or stimulatory, on tumor growth.

Combined effect of levan and cytotoxic agents on the growth of experimental tumours in mice.

The combined effect of the polysaccharide levan (previously shown to exert a host-dependent as well as direct antitumoural activity) and the cytotoxic agents cyclophosphamide (CY), methotrexate (MTX), vincristine (VINC) and 5-fluoro-uracil (SFU) was studied in Lewis lung carcinoma and AKR lymphoma. Combined chemo- and immunotherapy was applied beginning on the day of tumour cell inoculation. Additive effects were obtained with the combined treatments, compared to single treatments, with all the combinations except MTX-levan in Lewis lung carcinoma, where the combined effect was synergistic. The additive effect was obtained with different doses and routes of chemotherapy, whether local or intraperitoneal. A 2 mg dose of CY combined with levan administered at daily doses of 10 mg, resulted in a 100% prevention of Lewis lung carcinoma growth. It is suggested that the levan may have two beneficial effects: it can exert an inhibitory effect on tumour growth and diminish the deleterious effect of cytotoxic agents on the immune system.

Effect of administration schedule on the levan-cyclophosphamide combined treatment of Lewis lung carcinoma.

Combined treatment with levan and cyclophosphamide (CY) was applied intratumorally to Lewis lung carcinoma tumors in C57B1 mice on day 5 after tumor cell inoculation. Although on that day levan alone had no effect and CY alone caused only temporary regression of tumors, the combined CY-levan treatment caused 60% cure. Levan given before CY was almost as effective as simultaneous administration of both drugs on day 5. Delaying the administration of levan after CY treatment reduced the therapeutic effect. It is concluded that timing in relation to tumor cell inoculation as well as the order of administration of drugs, determine the degree of therapeutic efficacy. In tumor chemo-immunotherapy the final effect is probably due not only to the anti-tumoral effect per se of each drug, but also to the fact that the two agents have an effect on the immune system. Since the immune response may change during tumor development, the effect of timing of administration of an immunomodulator and certainly to two immunomodulators, can be crucial.

Mechanism of the inhibitory effect of levan on experimental tumors.

The mechanism of the antitumoral effect of levan was studied in the C57BL mice-Lewis lung carcinoma system. Modulation of host immune response and a direct inhibitory effect on tumor cells were found. Local treatment was more effective when begun early. It reduced tumor incidence without affecting the size of developing tumors. Systemic treatment was more effective when started late, inhibiting equally the tumor size in all mice. Macrophages are involved in local, lymphocytes possibly in systemic, inhibition. A direct effect on tumor cells was suggested by a decrease in oncogenicity, following preincubation with levan. Levan augments the antitumoral effect of cyclophosphamide in vivo and in vitro.