High incidence of large bore temporary hemodialysis catheter malfunction in patients with COVID-19 related kidney injury

PURPOSE

To evaluate the incidence of large bore hemodialysis catheter malfunction in the setting of COVID-19.

MATERIALS AND METHODS

A retrospective review was performed of all patients who underwent placement of a temporary hemodialysis catheter after developing kidney injury after COVID-19 infection at our institution. Data collected included demographic information, procedure related information, and incidence of replacement due to lumen thrombosis. Groups were compared using students t-test for continuous variables and Fisher's exact test for nominal variables.

RESULTS

Sixty-four patients (43M, mean age 63.2 ± 13.3) underwent placement of temporary hemodialysis catheter placement for kidney injury related to COVID 19 infection. Thirty-one (48.4%) of catheters were placed via an internal jugular vein (IJV) access and 33 (52.6%) of catheters were placed via a common femoral vein (CFV) access. Overall, 15 (23.4%) catheters required replacement due to catheter dysfunction. There were no differences in demographics in patients who required replacement to those who did not (p > 0.05). Of the replacements, 5/31 (16%) were placed via an IJV access and 10/33 (30.3%) were placed via a CFV access (p = 0.18). The average time to malfunction/replacement was 7.8 ± 4.8 days for catheters placed via an IJ access versus 3.4 ± 3.3 days for catheters placed via a CFV access (p = 0.055).

CONCLUSION

A high incidence of temporary dialysis catheter lumen dysfunction was present in patients with COVID-19 infection. Catheters placed via a femoral vein access had more frequent dysfunction with shorter indwelling time.

Pott's Puffy Tumor: Intracranial Extension Not Requiring Neurosurgical Intervention

Pott’s puffy tumor, typified by a subperiosteal abscess underlying the frontal bone, is an uncommonly encountered clinical entity that can occur in the setting of local trauma or secondary to frontal sinusitis. Diagnosis can be challenging, as cultures may be sterile, and the condition must be differentiated from neoplasm and superficial and soft tissue infection. Although more common in the pediatric population, Pott’s puffy tumor must remain on the differential with a high index of suspicion in adult patients who fit the clinical picture. Early diagnosis with CT or MRI and therapeutic medical and surgical intervention are crucial as intracranial complications, such as abscess and empyema can occur and may be fatal. We present an adult patient with a history of inhaled drug abuse who presented with Pott’s puffy tumor with meningitis and bifrontal epidural abscesses at presentation. There is evidence in the literature that management of sinus-related intracranial epidural abscess with antibiotic therapy and adequate surgical or endoscopic surgical drainage may bypass the need for neurosurgical intervention, as was the case here.

Liquid Storage of Hematopoietic Stem Cells Versus Proliferative Potential Colony-Forming Unit Granulocyte-Monocytes: Validation of Cell Processing

BACKGROUND

The material for transplantation must be of the highest quality. As far as we know, short-term storage is one of the crucial points of stem cell banking. According to the quality assurance system in a stem cell bank, each step of cell processing must be validated. The aim of this study was to assess the influence of short-term storage conditions into a clonogenic assay.

METHODS

Material was collected from mobilized peripheral blood by means of leukapheresis from 15 patients. Samples were stored at 4°C and 20°C; samples were evaluated on the day of leukapheresis and after 24 hours and after 48 hours of storage. The number of colony-forming unit granulocyte-monocyte (CFU-GM) precursors was analyzed with the use of in vitro culture. The material was evaluated before freezing and after thawing.

RESULTS

The average number of CFU-GM precursors in the material stored at 4°C before freezing on the day of collection was 84/10(5) nuclear cells (nc) and after 24 hours and 48 hours of storage was, respectively, 62/10(5) nc (P = .011719) and 36/10(5) nc (P = .02088). The average of the CFU-GM precursors in material stored at 20°C after 24 hours and 48 hours of storage amounted to 33/10(5) nc (P = .004439) and 2/10(5) nc (P = .00346), respectively.

CONCLUSIONS

In our study, the number of colonies of CFU-GM after 24 hours and 48 hours of storage, both at 4°C and 20°C, was significantly reduced compared with the number of colonies on the day of collection. Significantly greater numbers of CFU-GM precursors were observed in the material stored before freezing at 4°C in comparison with the material stored at 20°C.

Banking of Hematopoietic Stem Cells: Influence of Storage Time on Their Quality Parameters

BACKGROUND

Banking of hematopoietic stem cells (HSCs) is a rapidly growing part of the transplant field. The essence of the banking process is to maintain the optimal quality parameters throughout the storage period, allowing successful transplantation.

METHODS

Our laboratory research was carried out on 126 HSC samples that were collected by means of leukapheresis from patients with lymphoproliferative diseases. The samples were frozen in a controlled rate and stored up to 76 months in containers in vapor phase of liquid nitrogen. The evaluation was performed after thawing the probes. Viability of nuclear cells was assessed after incubation in Trypan blue, CD34+ phenotype cells were determined by means of cytometry with the use of 7-aminoactinomycin D (7-AAD), and an analysis of the proliferative potential of granulocyte-monocyte precursors was performed. For comparative statistical analysis, the material was divided into 3 groups according to storage time: A: <1 month (n = 45); B: 1-12 months (n = 50); C: >12 months (n = 31).

RESULTS

In the examined groups, similar median values were observed of nuclear cell viability (A, 86%; B, 87%; and C, 83%) and CD34+ cells (95%, 94.5%, and 95.8%, respectively). A gradual, nonsignificant, reduction in the median of granulocyte-monocyte precursors was found: 68 × 10(4)/kg of body weight (kg bw), 48.5 × 10(4)/kg bw, and 47 × 10(4)/kg bw, respectively. Statistical analysis with the use of the Kruskal-Wallis test showed a P value of >.05 for all variables.

CONCLUSIONS

There were no significant differences in the viability of nuclear cells, CD34+ cells, and proliferative potential granulocyte-monocyte precursors between groups. Storage for up to 76 months does not change the essential quality parameters, and HSCs could be qualified for distribution.

Analysis of the effect of cryoprotectant medium composition to viability of autologous hematopoietic cells collected by leukapheresis

OBJECTIVES

Cryopreservation of hematopoietic stem cells intended for autologous transplantation is a crucial element of the banking process. Although cryopreservation techniques are well known, improvement is needed. This study was designed to optimize cryopreservation to improve the quantitative and qualitative parameters of hematopoietic stem cells in the material intended for transplantation. We used available opportunities to provide the best quantitative and qualitative parameters of hematopoietic stem cell transplants processed in a closed system.

MATERIAL AND METHODS

Two hundred forty-eight products of hematopoietic stem cells collected by leukapheresis from patients with lymphoproliferative disorders create the basis of this report. The material was frozen in a controlled-rate freezer and stored in containers in the vapor phase of LN2 (-160°C). The composition of a cryoprotectant medium was modified. For freezing, 192 probes were used with a cryoprotective medium containing 20% dimethyl sulfoxide (DMSO) and enriched RPMI 1640. For 56 samples, we used 20% DMSO in autologous plasma harvested during leukapheresis. Products of hematopoietic stem cells and cryoprotectant medium were combined in a 1:1 ratio. The final number of nuclear cells did not exceed 2 × 10(8)/mL. Analysis was performed after thawing the probes. Viability of nuclear cells has been assessed using the microscopic technique after incubation in Trypan blue and the CD34+ cells by flow cytometry using the 7-aminoactynomycin D. A statistical analysis has been conducted using the Statistica program (StatSoft, Cracow, Poland).

RESULTS AND CONCLUSIONS

The results show that the application of autologous plasma is linked with higher viability of nuclear cells and CD34+ cells. Moreover, statistical analysis of the nuclear cells and CD34+ cells viability differs significantly between groups frozen using RPMI 1640 and autologous plasma (P < .05). To assess the viability of CD34+, cells frozen using RPMI 1640 results showed a large span of at 16.4% to 99.1% living cells.

Three-dimensional positioning of B chromosomes in fibroblast nuclei of the red fox and the chinese raccoon dog

Great progress has been achieved over the last years in studies on chromosome arrangement in mammalian cell nuclei. Growing evidence indicates that the genome's spatial organization is of functional relevance. So far, no attention has been paid to the nuclear organization of B chromosomes (Bs). In this study we have examined nuclear positioning of Bs in 2 species from the Canidae family--the red fox and the Chinese raccoon dog. Using 2D and 3D fluorescence in situ hybridization and 2 gene-specific probes (C-KIT and PDGFRA), we analyzed the location of Bs in fibroblast nuclei. We found that small Bs of the red fox occupied mostly the interior of the nucleus, while medium-sized Bs of the Chinese raccoon dog were observed in the peripheral area of the nucleus as well as in intermediate and interior locations. The more uniform distribution of B chromosomes in the Chinese raccoon dog may be the result of differences in their size, since 3 morphological types of Bs are distinguished in this species. Our results indicate that 3D positioning of B chromosomes in fibroblast nuclei of the 2 canid species is in agreement with the chromosome size-dependent theory.

Evaluation of the quality of postharvest rapeseed by means of an electronic nose

BACKGROUND

Rapeseed is a valuable source of edible oil. The presence of even a small amount of mouldy or burnt rapeseed in a particular production batch deteriorates the quality of the edible oil obtained from it. Since the traditional method of using a panel of experts is time-consuming, there is a need for fast and easy methods for rapeseed quality evaluation by intelligent devices to replace human labour.

RESULTS

For rapeseed quality evaluation, an electronic nose equipped with an array of eight quartz microbalance sensors and four metal oxide semiconductor sensors was used. Signals generated by the sensors were analysed by principal component analysis and discriminant function analysis. Identification of samples that contained small proportions of mouldy or burnt rapeseed was possible despite the differences between the particular varieties studied.

CONCLUSION

Electronic nose technology has shown the possibility of detecting samples of faulty rapeseed at very low contamination levels and distinguishing them with high probability from sound rapeseed.

Can von Willebrand factor, platelet-endothelial cell adhesion molecule-1 and thrombomodulin be used as alternative markers of endothelial cell injury in human glomerulonephritis?

PURPOSE

There is growing evidence that endothelial cells (EC) are active participants of an inflammatory process in glomeruli.

MATERIAL AND METHODS

We compared the glomerular expression of three EC-coupled molecules, i.e. platelet-endothelial cell adhesion molecule-1 (PECAM-1 or CD31), von Willebrand factor (vWF) and thrombomodulin (TM) in 60 patients with glomerulonephritis (GN) and five normal kidneys (NK). The alkaline phosphatase anti-alkaline phosphatase method was used to examine the expression of these proteins in the biopsy specimens.

RESULTS

In NK, the expression of CD31 and vWF comprised the whole glomerular network. In contrast, the expression of TM was much lower and localized mainly to EC at the vascular pole and adjacent areas. In GN, the glomerular staining for CD31 and vWF was significantly reduced. A fall in the expression of both these EC antigens was more pronounced in proliferative forms of GN (PGN) than in non-proliferative GN (NPGN) (CD31: NPGN vs. PGN, p < 0.02; vWF: NPGN vs. PGN, p < 0.05). In addition, a linear relationship between the expression of CD31 and vWF was found in GN (r = 0.8, p < 0.001). Conversely to CD31 and vWF, a marked increase in glomerular reactivity for TM was observed in all the patients with GN (GN: 2.12 +/- 0.32, NK: 0.95 +/- 0.05, p < 0.02). However, the highest expression of TM was found in membranoproliferative GN and lupus GN.

CONCLUSIONS

Our results suggest that CD31 and vWF may be used as markers of glomerular EC loss during GN, whereas TM staining seems to reflect EC activation in response to circulating and/or released in situ procoagulant factors.

Expression of two alternative transcription forms of platelet-derived growth factor-A chain in the normal human kidney and in glomerulonephritis

PURPOSE

Up to now, a role of platelet-derived growth factor (PDGF)-AA in glomerulonephritis (GN) remains unclear. PDGF-A chain may be produced in two forms, as a result of the alternative splicing.

MATERIAL AND METHODS

We examined the expression of this growth factor in the renal tissue of 57 patients with GN and seven normal kidneys (NK). The gene expression of PDGF-A was examined by reverse transcriptase-polymerase chain reaction. Sets of primers allowing distinction between the two forms of transcripts were used. Specificity of the PCR products was confirmed by restriction enzyme analysis and sequencing. The expression of PDGF-AA/AB was also evaluated by immunohistochemistry.

RESULTS

Compared to NK, the expression of PDGF-A gene was higher in the renal tissue with GN. This expression was higher in non-proliferative GN (NPGN) than in proliferative forms of GN (PGN) (1.24 +/- 0.34 vs. 0.86 +/- 0.14). In NK, both forms of transcripts (N = 4) or only the short one (N = 3) were found. In 45.5% of patients with NPGN, only the short form could be detected. In contrast, in 68.6% of patients with PGN both or only the longer form of transcripts were found. In NK, a faint staining for PDGF-AA/AB was observed within glomerular capillaries, whereas a statistically significant increase in this protein expression was particularly stated in NPGN. These results suggest that the production of the longer PDGF-A chain variant is associated with glomerular cells' proliferation. However, the higher expression of PDGF-AA/AB protein in NPGN could indicate an essential role of this growth factor in the maintaining the glomerular architecture.