Local prolonged release of antibiotic for prevention of sternal wound infections postcardiac surgery-A novel technology.

INTRODUCTION: Sternal wound infection (SWI) is a devastating postcardiac surgical complication. D-PLEX100 (D-PLEX) is a localized prolonged release compound applied as a prophylactic at the completion of surgery to prevent SWI. The D-PLEX technology platform is built as a matrix of alternating layers of polymers and lipids, entrapping an antibiotic (doxycycline). The objective of this study was to assess the safety profile and pharmacokinetics of D-PLEX in reducing SWI rates postcardiac surgery. METHOD: Eighty-one patients were enrolled in a prospective single-blind randomized controlled multicenter study. Sixty patients were treated with both D-PLEX and standard of care (SOC) and 21 with SOC alone. Both groups were followed 6 months for safety endpoints. SWI was assessed at 90 days. RESULTS: No SWI-related serious adverse events (SAEs) occurred in either group. The mean plasma Cmax in patients treated with D-PLEX was about 10 times lower than the value detected following the oral administration of doxycycline hyclate with an equivalent overall dose, and followed by a very low plasma concentration over the next 30 days. There were no sternal infections in the D-PLEX group (0/60) while there was one patient with a sternal infection in the control group (1/21, 4.8%). CONCLUSION: D-PLEX was found to be safe for use in cardiac surgery patients. By providing localized prophylactic prolonged release of broad-spectrum antibiotics, D-PLEX has the potential to prevent SWI postcardiac surgery and long-term postoperative hospitalization, reducing high-treatment costs, morbidity, and mortality.

D-PLEX500: a local biodegradable prolonged release doxycycline-formulated bone graft for the treatment for peri-implantitis. A randomized controlled clinical study.

OBJECTIVES: In the present pilot, multicenter, randomized, single-blinded, controlled study, surgical treatment with or without the administration of D-PLEX500 (a biodegradable prolonged release local doxycycline formulated with ß-tricalcium phosphate bone graft) was accessed for the treatment of peri-implantitis. METHOD AND MATERIALS: Subjects undergoing surgical treatment for intrabony peri-implantitis defects after flap elevation were randomly assigned, to adjunct D-PLEX500 placement group or to control group. Clinical and radiographic parameters were measured at 6 and 12 months. RESULTS: Twenty-seven subjects (average age: 64.81 ± 7.61 years) were enrolled; 14 patients (18 implants) were randomized to the test group and 13 (14 implants) to the control group. There was no difference in plaque scores between the groups. There was no difference in the changes of mean periodontal probing depth between the test and control groups between baseline and the 6-month follow-up, whereas statistically significant difference was observed after 12 months' follow-up when analyzed for all sites averaged. There was a statistically significant difference in the changes of clinical attachment levels and radiographic bone levels between the groups between baseline and 12 months. These improvements were demonstrated when analyzed at both implant and subject levels. Only D-PLEX500 treatment led to improved bone levels at both time points. The improvement in bone levels was significant in the D-PLEX500 treatment group already after 6 months, and further improved over the 12-month follow-up. Implants were lost only in the control group (14%). CONCLUSIONS: D-PLEX500 sustained release local antibiotic formulated with bone filler showed promising results in enabling healing of peri-implantitis lesions. The antibacterial component of the bone graft material might create favorable conditions that enable implant surface decontamination and soft and hard tissue healing over a prolonged period.

A doxycycline-loaded polymer-lipid encapsulation matrix coating for the prevention of implant-related osteomyelitis due to doxycycline-resistant methicillin-resistant Staphylococcus aureus.

Implant-associated bone infections caused by antibiotic-resistant pathogens pose significant clinical challenges to treating physicians. Prophylactic strategies that act against resistant organisms, such as methicillin-resistant Staphylococcus aureus (MRSA), are urgently required. In the present study, we investigated the efficacy of a biodegradable Polymer-Lipid Encapsulation MatriX (PLEX) loaded with the antibiotic doxycycline as a local prophylactic strategy against implant-associated osteomyelitis. Activity was tested against both a doxycycline-susceptible (doxy(S)) methicillin-susceptible S. aureus (MSSA) as well as a doxycycline-resistant (doxy(R)) methicillin-resistant S. aureus (MRSA). In vitro elution studies revealed that 25% of the doxycycline was released from the PLEX-coated implants within the first day, followed by a 3% release per day up to day 28. The released doxycycline was highly effective against doxy(S) MSSA for at least 14days in vitro. A bolus injection of doxycycline mimicking a one day release from the PLEX-coating reduced, but did not eliminate, mouse subcutaneous implant-associated infection (doxy(S) MSSA). In a rabbit intramedullary nail-related infection model, all rabbits receiving a PLEX-doxycycline-coated nail were culture negative in the doxy(S) MSSA-group and the surrounding bone displayed a normal physiological appearance in both histological sections and radiographs. In the doxy(R) MRSA inoculated rabbits, a statistically significant reduction in the number of culture-positive samples was observed for the PLEX-doxycycline-coated group when compared to the animals that had received an uncoated nail, although the reduction in bacterial burden did not reach statistical significance. In conclusion, the PLEX-doxycycline coating on titanium alloy implants provided complete protection against implant-associated MSSA osteomyelitis, and resulted in a significant reduction in the number of culture positive samples when challenged with a doxycycline-resistant MRSA.

Computerized cell-scanning system for evaluating human spermatogenesis in non-obstructive azoospermic patients.

There may be incompatibility between testicular histopathological evaluation and testicular sperm extraction (TESE) outcome. Assessment for sperm presence and different pathological disturbances of non-obstructive azoospermia (NOA) remains challenging. An assay for maximal sampling and accurate identification of testicular cells from NOA patients undergoing TESE and autopsied fertile controls was developed. Testicular cells stained and scanned automatically for morphology underwent fluorescence in-situ hybridization using centromeric probes for chromosomes X, Y and 18 after destaining. Cells were automatically classified according to ploidy, and ratios of haploid cells and autosomal (18) and sex-chromosome bivalent rates were calculated. Identification of testicular cells in suspension enabled prediction of spermatogenesis in seven of eight Sertoli-cell-only syndrome patients. Haploid/diploid cell ratios were 67.6:32.2 for controls and 9.6:90.4 for patients. Both autosomal (18) and sex-chromosome bivalents were present in patients (4.1 ± 5.82%) and controls (19.7 ± 8.95%). Few tetraploid pachytene spermatocytes were observed. More secondary spermatocytes with NOA showed two distinct signals for chromosome 18 (27.9 ± 32.69%) compared with controls (0.4 ± 0.35%). The computerized cell-scanning system enables simultaneous application of morphology and chromosome analysis of testicular cells, which enhance assessing different pathological disturbances and estimating the likelihood of a successful second TESE procedure.

Acquisition of a Ph chromosome with minor BCR/ABL fusion in treatment-related myelodysplastic syndrome with chromosome 7 abnormalities in a patient treated for Hodgkin disease.

The patient reported in this study originally had Hodgkin disease that was treated heavily with multiple courses of combined chemotherapy and radiotherapy. Secondary myelodysplastic syndrome (MDS) with a complex karyotype with monosomy 7, deletion 7q31, and double deletion 7q31 developed 8 years later. During the course of the disease, conventional cytogenetics and interphase FISH (I-FISH) analysis detected a Ph chromosome and BCR/ABL fusion with mBCR rearrangement. Using a multiparametric cell scanning system that enables combined analysis with probes specific for 7/7q- and BCR/ABL in a single cell, we were able to demonstrate the presence of the BCR/ABL fusion only in cells with monosomy of chromosome 7 and 7q31 deletion, but not in cells with a normal chromosome 7 or with a double deletion of 7q31. We propose two possible models that may explain the appearance of the BCR/ABL fusion in the pre-existing treatment-related MDS clones characterized by chromosome 7 rearrangements.

Determination of chromosome 13 status in bone marrow cells of patients with multiple myeloma using combined morphologic and fluorescence in situ hybridization analysis.

Deletion of chromosome 13q is believed to be an adverse prognostic marker in patients with multiple myeloma (MM). Interphase fluorescence in situ hybridization (I-FISH) is the method of choice for detection of chromosome 13q deletion (del13q). However, I-FISH has high false-positive rates attributed to a low percentage of plasma cells (PC), which are responsible for MM, in bone marrow (BM) samples from MM patients. In an attempt to overcome this problem, combined morphologic and I-FISH analyses were performed by a unique system that allows rapid automatic scanning of a large number of cells with simultaneous determination of the lineage of specific cells carrying del13q. The percentage of PC with del13q in BM samples from 40 MM patients was calculated. In addition, we established a useful prognostic ratio defined as the number of PC with del13q divided by the number of non-PC with del13q (PDP/PDNP), which may help to precisely define the putative role of del13q in prediction response of MM patients to new therapeutic compounds. We suggest this technique as a novel sensitive and specific method for detection of del13q in a minor PC population of MM patients.

Combined analysis of morphology and fluorescence in situ hybridization in follow-up of minimal residual disease in a child with Philadelphia-positive acute lymphoblastic leukemia.

The past decade has brought new technologies to the study of minimal residual disease (MRD) in leukemia. Each of them has limitations and is far from being accurate. Recently, a new multiparametric cell scanning system (Duet) was introduced to the field of MRD detection. This system has the advantage of automatically scanning large numbers of cells and performing combined analysis of morphology and fluorescence in situ hybridization (FISH) on the same cell. We used this system to characterize the lineage and degree of maturation of the cells carrying the minor m-BCR/ABL fusion, in a follow-up of an 8-year-old boy with Philadelphia-positive (Ph(+)) acute lymphoblastic leukemia (ALL). The boy was treated using a high-risk protocol and was closely monitored with FISH analysis for cells carrying the m-BCR/ABL fusion. Consecutive analysis along 2.5 years from remission showed 0.2-4.5% m-BCR/ALB(+) cells in the peripheral blood (PB), which is within the accepted background range for this method. The combined analysis found that all the m-BCR/ABL(+) cells were mature lymphocytes. Because mature lymphocytes have a long life span in the circulation, this finding supports the fact that the patient is in remission. Moreover, since mature differentiated cells have a low proliferative capacity, there is a low risk for relapse.