The acute effects of CMF-based chemotherapy on maxillary periodontal microcirculation

Oral and post-transplantation infectious status in patients with hematopoietic stem cell transplants: A prospective observational study

OBJECTIVE

Infectious status may be life threatening in hematopoietic stem cell transplant (HSCT) recipients. The aim of this study was to evaluate the effect of oral status on infectious conditions during the neutropenic phase after HSCT.

STUDY DESIGN

Seventy patients with various hematologic malignancies were involved. Before HSCT, oral and periodontal examination, including the number of teeth and decayed, missing, and filled teeth index (DMFT); visible plaque (%); bleeding on probing (BOP [%]); clinical attachment level; and probing depth (PD) values were collected. Daily blood cultures were collected and analyzed in terms of infection-related parameters, including febrile neutropenia (FN), bacteremia, and C-reactive protein (CRP) during the neutropenic phase of HSCT.

RESULTS

Forty-two patients (60%) received autologous and 28 (40%) allogeneic HSCT. In both groups, patients without FN after HSCT had significantly lower DMFT index scores and fewer sites with PD ≥4 mm (P < .05). However, bacteremia, FN, and CRP were similar in patients with periodontitis compared with non-periodontitis patients (P > .05).

CONCLUSIONS

The results suggest that periodontal status may not significantly impact the infection-related parameters in patients treated for HSCT. However, DMFT and the prevalence of sites with PD ≥4 mm may be involved in febrile neutropenia.

Sublingual microvascular perfusion is altered during normobaric and hyperbaric hyperoxia

Hyperoxia and hyperbaric oxygen therapy can restore oxygen tensions in tissues distressed by ischemic injury and poor vascularization and is believed to also yield angiogenesis and regulate tissue perfusion. The aim of this study was to develop a model in which hyperoxia-driven microvascular changes could be quantified and to test the hypothesis that microcirculatory responses to both normobaric (NB) and hyperbaric (HB) hyperoxic maneuvers are reversible. Sublingual mucosa microcirculation vessel density, proportion of perfused vessels, vessel diameters, microvascular flow index, macrohemodynamic, and blood gas parameters were examined in male rabbits breathing sequential O2/air mixtures of 21%, 55%, 100%, and return to 21% during NB (1.0 bar) and HB (2.5 bar) conditions. The results indicate that NB hyperoxia (55% and 100%) produced significant decreases in microvascular density and vascular diameters (p<0.01 and p<0.05, respectively) accompanied by significant increases in systolic and mean arterial blood pressure (p<0.05, respectively) with no changes in blood flow indices when compared to NB normoxia. HB normoxia/hyperoxia resulted in significant decreases in microvascular density (p<0.05), a transient rise in systolic blood pressure at 55% (p<0.01), and no changes in blood vessel diameter and blood flow indices when compared to NB hyperoxia. All microcirculation parameters reverted back to normal values upon return to NB normoxia. We conclude that NB/HB hyperoxia-driven changes elicit reversible physiological control of sublingual mucosa blood perfusion in the presence of steady cardiovascular function and that the absence of microvascular vasoconstriction during HB conditions suggests a beneficial mechanism associated with maintaining peak tissue perfusion states.

Periodontal status and bacteremia with oral viridans streptococci and coagulase negative staphylococci in allogeneic hematopoietic stem cell transplantation recipients: a prospective observational study

AIM

This study was aimed to investigate whether any association could be found between the presence of an inflamed and infected periodontium (e.g., gingivitis and periodontitis) and the development of bacteremia during neutropenia following allogeneic hematopoietic stem cell transplantation (HSCT).

METHODS

Eighteen patients underwent a periodontal examination before HSCT. Patients were classified as periodontally healthy [all periodontal pocket depths (PPD) ≤ 4 mm and bleeding on probing (BOP) ≤ 10%) or as having gingivitis/periodontitis (PPD ≥ 4 mm and BOP > 10%]. Oral mucositis (OM) was scored using the daily mucositis score. Blood cultures were taken at least twice weekly.

RESULTS

Five patients were periodontally healthy, while 13 patients had gingivitis or periodontitis. Twelve patients (67%) developed bacteremia during neutropenia, of which 11 patients (61%) had one or more episodes of bacteremia due to coagulase-negative staphylococci (CONS, most often Staphylococcus epidermidis) or to oral viridans streptococci (OVS), or both. Patients with gingivitis/periodontitis more often had bacteremia than those with a healthy periodontium (p = 0.047), and BOP was associated with bacteremia (p = 0.049). All patients developed ulcerative OM, but its severity and duration were not associated with bacteremia. OM duration and the length of stay in the hospital were strongly correlated (R = 0.835, p ≤ 0.001).

CONCLUSION

This study indicates that periodontal infections may contribute to the risk of developing OVS and CONS bacteremia during neutropenia following HSCT. While our results point to the importance of periodontal evaluation and management before HSCT, further studies on periodontal contribution to systemic infectious complications are warranted.

The influence of zoledronic acid and cyclophosphamide on microcirculation regeneration in healing oral mucosal flaps

The use of intravenous nitrogenous bisphosphonates and antineoplastic agents as postoperative adjuvant cancer management strategies may influence the course of oral wound healing by altering tissue vascularisation kinetics. The aim of this study was to investigate if single or combined zoledronic acid (ZOL) and cyclophosphamide (CTX) would influence microcirculation regeneration in healing oral mucosal flaps. Twenty female specific-pathogen free New Zealand white rabbits were randomised into four groups. In all animals a mucosal flap was raised; three groups were treated each separately with intravenous infusions of 0.14mg/kg ZOL, 100mg/kg CTX, or both, respectively. The fourth group was used as a control. Capillary density measurements, expressed as the mean number of capillaries±SD per mm(2) (cpll/mm(2)), was performed preoperatively using sidestream dark-field (SDF) imaging and repeated immediately postoperatively and on days 2, 4, 7, 9, 11, 14, and 21. Whole blood count and body weight was assessed in each group to monitor pharmacotherapeutic responses. Preoperative mean capillary density was 74±8cpll/mm(2) and 40±11cpll/mm(2) directly after surgery (P<0.0001). Post hoc comparisons of follow-up SDF measurements on days 9-21 between control and ZOL vs. CTX and ZOL+CTX were statistically significant (P<0.05). The present study demonstrates that ZOL did not alter capillary regeneration in healing mucosal flaps. However, although the early healing phase is generally characterised by rapid progression of capillary regeneration, interventions with CTX and ZOL+CTX significantly altered capillary regeneration and persisted beyond the third postoperative week.

Validation of near-infrared laser speckle imaging for assessing microvascular (re)perfusion

The present study was conducted to compare laser speckle imaging (LSI) with sidestream dark field (SDF) imaging (i.e., capillary microscopy) so as to validate the use of LSI for assessing microvascular (re)perfusion. For this purpose, LSI and SDF measurements were performed on the human nail fold during gradual occlusion of the upperarm circulation to modify nail fold perfusion under controlled circumstances. Additionally, a vascular occlusion test was performed to test the ability of LSI to detect rapid changes in tissue perfusion during reactive hyperemia and a hyperthermic challenge was performed to measure LSI perfusion at maximum functional capillary density. Normalized LSI measurements (i.e., normalized to baseline is 100%) were shown to correlate positively with normalized SDF measurements (Pearson's r=0.92). This was supported by linear regression analysis (slope of 1.01, R(2)=0.85, p<0.001). During the vascular occlusion test, LSI perfusion decreased from 307+/-90 AU (baseline) to 42+/-8 AU (ischemia). Peak perfusion during reperfusion was 651+/-93 AU (212% of baseline), which had returned to baseline after 2 min. Hyperthermia increased LSI perfusion from 332+/-90 AU to 1067+/-256 AU (321% of baseline). The main finding was that changes in perfusion as measured by LSI correlated well with changes in capillary red blood cell velocities as measured by SDF imaging during controlled reduction of the (micro)vascular perfusion. It was further shown that LSI is capable of measuring tissue perfusion at high temporal and spatial resolution. In conclusion, LSI can be employed to accurately quantitate microvascular reactivity following ischemic and hyperthermic challenges.