Periodontal Inflammation Primes the Systemic Innate Immune Response.

The presence of periodontal diseases (PDs) often strongly correlates with other severe chronic inflammatory conditions, including cardiovascular disease, diabetes, and arthritis. However, the mechanisms through which these diseases interact are unclear. In PD, tissue and bone destruction in the mouth is driven by elevated recruitment of polymorphonuclear neutrophils (PMNs), which are primed and recruited from the circulation to sites of inflammation. We predicted that systemic effects on PMN mobilization or priming could account for the interaction between PD and other inflammatory conditions. We tested this using a mouse model of ligature-induced PD and found elevated PMN counts specifically in bone marrow, supporting a systemic effect of periodontal tissue inflammation on PMN production. In contrast, mice with induced peritonitis had elevated PMN counts in the blood, peritoneum, and colon. These elevated counts were further significantly increased when acute peritonitis was induced after ligature-induced PD in mice, revealing a synergistic effect of multiple inflammatory events on PMN levels. Flow cytometric analysis of CD marker expression revealed enhanced priming of PMNs from mice with both PD and peritonitis compared to mice with peritonitis alone. Thus, systemic factors associated with PD produce hyperinflammatory PMN responses during a secondary infection. To analyze this systemic effect in humans, we induced gingival inflammation in volunteers and also found significantly increased activation of blood PMNs in response to ex vivo stimulation, which reverted to normal following resolution of gingivitis. Together, these results demonstrate that periodontal tissue inflammation has systemic effects that predispose toward an exacerbated innate immune response. This indicates that peripheral PMNs can respond synergistically to simultaneous and remote inflammatory triggers and therefore contribute to the interaction between PD and other inflammatory conditions. This suggests larger implications of PD beyond oral health and reveals potential new approaches for treating systemic inflammatory diseases that interact with PD.

Resolving Macrophages Counter Osteolysis by Anabolic Actions on Bone Cells.

Progression of inflammatory osteolytic diseases, including rheumatoid arthritis and periodontitis, is characterized by increased production of proinflammatory mediators and matrix-degrading enzymes by macrophages and increased osteoclastic activity. Phenotypic changes in macrophages are central to the healing process in virtually all tissues. Using a murine model of periodontitis, we assessed the timing of macrophage phenotypic changes and the impact of proresolving activation during inflammatory osteolysis and healing. Proinflammatory macrophage activation and TNF-α overproduction within 3 wk after induction of periodontitis was associated with progressing bone loss. Proresolving activation within 1 wk of stimulus removal and markers of resolving macrophages (IL-10, TGF-ß, and CD206) correlated strongly with bone levels. In vivo macrophage depletion with clodronate liposomes prevented bone resorption but impaired regeneration. Induction of resolving macrophages with rosiglitazone, a PPAR-γ agonist, led to reduced bone resorption during inflammatory stimulation and increased bone formation during healing. In vitro assessment of primary bone marrow-derived macrophages activated with either IFN-γ and LPS (proinflammatory activation) or IL-4 (proresolving activation) showed that IL-4-activated cells have enhanced resolving functions (production of anti-inflammatory cytokines; migration and phagocytosis of aged neutrophils) and exert direct anabolic actions on bone cells. Cystatin C secreted by resolving but not inflammatory macrophages explained, in part, the macrophage actions on osteoblasts and osteoclasts. This study supports the concept that therapeutic induction of proresolving functions in macrophages can recouple bone resorption and formation in inflammatory osteolytic diseases.

Oral and Blood Neutrophil Activation States during Experimental Gingivitis.

Polymorphonuclear neutrophils (PMNs) are the primary leukocytes present in the healthy and inflamed oral cavity. While unique PMN activation states have been shown to differentiate health and periodontitis, little is known about the changes in PMN activation states that occur during the transition from periodontal health to gingivitis. The objective of this study was to characterize oral and circulatory PMNs during induction and resolution of experimental gingivitis. Healthy volunteers were recruited to undergo experimental gingivitis. Clinical assessment of pocket depths, bleeding on probing, gingival index, and plaque index, as well as flow cytometric analysis of CD (cluster of differentiation) activation markers on blood and oral PMNs, was performed weekly. All clinical parameters increased significantly during the induction period and returned to baseline levels during the resolution phase. During the induction phase, while oral PMN counts increased, oral PMN activation state based on surface expression of CD63, CD11b, CD16, and CD14 was diminished compared to those seen in health and during the resolution phase. PMNs in circulation during onset showed increased activation based on CD55, CD63, CD11b, and CD66a. Using clinical parameters and oral PMN counts assessed at day 21, we noted 2 unique disease patterns where one-third of subjects displayed an exaggerated influx of oral PMNs with severe inflammation compared to the majority of the population who experienced a moderate level of inflammation and PMN influx. This supports the notion that PMN influx and severe inflammatory changes during gingivitis could identify subjects at risk for the development of severe gingival inflammation and progression toward destructive periodontitis. This study demonstrates that oral PMN activation states are reduced in gingivitis and suggest that only in periodontitis do PMNs become hyperactivated and tissue damaging. Knowledge Transfer Statement: Our article creates a paradigm for future studies of the evolution of essential oral and circulatory biomarkers to identify individuals at risk to develop periodontitis at an early stage of periodontal disease, which is reversible upon proper oral hygiene practices and dental treatments.

The learning curve with a new cephalomedullary femoral nail.

INTRODUCTION: The Cephalomedullary Nail (CMN) (Zimmer, Warsaw) was introduced in 2010 as part of a multicenter trial to evaluate its performance. At one year the CMN had results in keeping with other intramedullary devices with good union rates and low complication rates. In the second and third years of use an increased rate of implant failure was observed, towards the higher end of the 1-5% nail breakage rate seen in other studies. This study aims to evaluate if there any common features in this cohort of patients. MATERIALS AND METHODS: This is a retrospective cohort study looking at patients who underwent femoral fracture fixation using the cephalomedullary nail between January 2011 and June 2014. The primary outcome measure was implant failure; secondary outcomes were; fracture reduction and bisphosphonate use. RESULTS: 201 patients were included (135 female, 66 male) with an average age of 81 years. Ten (5%) nail breakages occurred in the study period at an average of 39 weeks (24-92); 9 were 125° nails 1 was a 130° nail and all fractured at the lag screw junction. CONCLUSIONS: Implant failure is a recognised complication of intramedullary nailing in cases of non-union. The increased rate of implant failure in our department required a change to a 130° CMN implant and a 3.2mm diameter guide wire for placement of the lag screw. We continue to monitor this difficult group of patients very closely.

Distinct Oral Neutrophil Subsets Define Health and Periodontal Disease States.

Neutrophils exit the vasculature and swarm to sites of inflammation and infection. However, these cells are abundant in the healthy, inflammation-free human oral environment, suggesting a unique immune surveillance role within the periodontium. We hypothesize that neutrophils in the healthy oral cavity occur in an intermediary parainflammatory state that allows them to interact with and contain the oral microflora without eliciting a marked inflammatory response. Based on a high-throughput screen of neutrophil CD (cluster of differentiation) marker expression and a thorough literature review, we developed multicolor flow cytometry panels to determine the surface marker signatures of oral neutrophil subsets in periodontal health and disease. We define here 3 distinct neutrophil subsets: resting/naive circulatory neutrophils, parainflammatory neutrophils found in the healthy oral cavity, and proinflammatory neutrophils found in the oral cavity during chronic periodontal disease. Furthermore, parainflammatory neutrophils manifest as 2 distinct subpopulations-based on size, granularity, and expression of specific CD markers-and exhibit intermediate levels of activation as compared with the proinflammatory oral neutrophils. These intermediately activated parainflammatory populations occur in equal proportions in the healthy oral cavity, with a shift to one highly activated proinflammatory neutrophil population in chronic periodontal disease. This work is the first to identify and characterize oral parainflammatory neutrophils that interact with commensal biofilms without inducing an inflammatory response, thereby demonstrating that not all neutrophils trafficking through periodontal tissues are fully activated. In addition to establishing possible diagnostic and treatment monitoring biomarkers, this oral neutrophil phenotype model builds on existing literature suggesting that the healthy periodontium may be in a parainflammatory state.

A novel multimedia workshop on portable cardiac critical care ultrasonography: a practical option for the busy intensivist.

We aimed to assess the role of a short duration multimedia workshop to improve the knowledge and skills in cardiac critical care ultrasonography. Thirty critical care physicians participated in the cardiac critical care ultrasonography workshop. Two weeks prior to hands-on training, a three-hour web-based didactic lecture was provided to learners. Hands-on training consisted of a two-hour examination on models without pathology and a 30-minute debriefing with instructors. Pre- and post-workshop knowledge tests were conducted online using 30 multiple choice questions. Pre- and post-workshop skill tests were video captured for evaluation by two reviewers to whom data were masked. Scores were based on 34 predetermined checklist items including learner performance, instrumentation and adequacy of ultrasound images. Learners' confidence levels on image acquisition were assessed using a ten-point Likert scale. A short duration multimedia, hands-on workshop improved intensivists' knowledge, skills and confidence levels on cardiac critical care ultrasonography image acquisition. Further studies are needed to assess the sustainability of observed improvements. This module may be a practical option for the acquisition and maintenance of cardiac critical care ultrasonography knowledge and skills.

Endothelin receptor antagonist therapy in congenital heart disease with shunt-associated pulmonary arterial hypertension: a qualitative systematic review.

BACKGROUND: Congenital heart disease (CHD) with systemic-topulmonary shunting is associated with pulmonary arterial hypertension (PAH). There are similar clinical and pathophysiological features between CHD with shunt-associated PAH and idiopathic PAH. Endothelin-receptor antagonists (ERAs) are oral medications that improve pulmonary hemodynamics, symptoms and functional capacity in many PAH patients. However, the role of ERAs in CHD with shunt-associated PAH is unclear. METHODS: MEDLINE, EMBASE and the Cumulative Index of Nursing and Allied Health Literature (CINAHL) databases were searched for articles published from 1966 through September 2006, as well as bibliographies of all retrieved papers. All published English-language studies of adult CHD patients with shunt-associated PAH treated with ERAs were reviewed for clinical, functional and hemodynamic outcomes. RESULTS: Ten studies of 174 adult CHD subjects with shunt-associated PAH were identified. Other than one placebo-controlled, randomized clinical trial, all studies were open-label, uncontrolled observational trials. Subjects were treated with the ERA bosentan for a mean (+/- SD) of 9+/-7 months. Nine studies reported improved World Health Organization (WHO) modification of the New York Heart Association functional class, with 95 of 164 subjects (58%) improving by at least one functional class. The 6 min walk distance improved in all eight studies in which it was assessed. Bosentan was generally well tolerated; 2.3% of subjects withdrew because of elevated liver enzymes. Two patients with WHO functional class IV PAH died during bosentan therapy. CONCLUSION: Treatment of CHD patients with shunt-associated PAH with the ERA bosentan is associated with an improvement in functional class and objectively measured exercise capacity. The consistency of the uncontrolled data and the positive results of a single randomized clinical trial suggest a role for ERA therapy in CHD patients with shunt-associated PAH. Caution is suggested when considering bosentan therapy for CHD patients with WHO functional class IV PAH.

Prefabricated and prelaminated flaps for head and neck reconstruction.

Flap prefabrication and prelamination are evolving, new techniques that are useful in reconstructing complex defects of the head and neck. Flap prefabrication involves the introduction of a new blood supply by means of a vascular pedicle transfer into a volume of tissue. After a period of neovascularization, this volume of tissue may be transferred, based only on its implanted vascular pedicle. The transfer may be local transposition or by microsurgical transfer. Flap prelamination refers to a technique in which additional tissue is added to an existing flap (without manipulation of its axial blood supply) to make a multilayered flap that may be used for complex, three-dimensional multilayered reconstructions. This technique may be used locally or at a distance, requiring microvascular transfer. Examples of each are described in this article.

Primary cysts in the iridociliary sulcus: ultrasound biomicroscopic features of 210 cases.

BACKGROUND: Primary cysts occur spontaneously, whereas secondary cysts arise following surgical or nonsurgical injury and can lead to further complications. We performed a study to observe and characterize primary iridociliary cysts through the examination of ultrasound biomicroscopic (UBM) images from affected patients. METHODS: The UBM images from 210 patients were analysed and the characteristics of each cyst were observed and recorded. The patients had been examined and received the diagnosis of iridociliary cysts between 1990 and early 1998 at a major referral centre for the diagnosis and treatment of cancer in Toronto. RESULTS: Of the 210 cysts 169 (80%) occurred in isolation, and the remainder occurred in the presence of a tumour. The mean horizontal diameter of the isolated cysts was 1.72 mm, and the mean vertical diameter was 1.04 mm. Isolated cysts were solitary in 101 cases (60%) and showed multiple loculations in 68 (40%). Solitary cysts were slightly larger than those with multiple loculations. Isolated cysts were associated with markedly narrowed or closed angles locally in 110 cases (65%). INTERPRETATION: Primary iridociliary cysts are common and need to be differentiated from iris and ciliary body tumours. UBM is a definitive method of diagnosing these lesions. Cysts can cause localized angle closure but rarely cause clinical complications. Cysts associated with anterior segment tumours may give an erroneous impression as to tumour size.

Optimization of conscious sedation in plastic surgery.

The administration of conscious sedation by the plastic surgeon must be safe, efficient, and consistent. In the proper setting, with trained staff and appropriate backup, conscious sedation can allow optimal patient satisfaction with expedient recovery in addition to cost containment. The highly effective local anesthesia afforded by dilute, high-volume ("tumescent") infiltration extends the use of conscious sedation to cases previously performed under general anesthesia or deep sedation. The purpose of this analysis was to identify variables in conscious sedation that affect traditional outcome parameters in ambulatory surgery, particularly the duration of recovery and adverse events such as nausea and emesis. All perioperative and operative records of 300 consecutive patients having plastic surgical procedures under conscious sedation were carefully reviewed. Patients were ASA class I or II by requisite. Conscious sedation followed a standardized administration protocol, using incremental doses of two agents: midazolam (0.25 to 1 mg) and fentanyl (12.5 to 50 mcg). A subset of patients received preoperative oral sedation. Multivariate statistical analysis was conducted using SPSS 8.0 for Windows (SPSS Inc., Chicago, Ill.). Of the 300 patients, same-day discharge was intended for 281. Eight procedure categories were defined. No anesthetic complications occurred. As expected, recovery time was significantly correlated with the duration and type of procedure (p < 0.001) and the total dosage of both intraoperative sedative agents (p < 0.001). Interestingly, a negative correlation with advancing age existed (p < 0.001), likely reflecting the significantly higher intraoperative sedative dosing in younger patients (p < 0.001). When controlled for the effects of procedure duration and intraoperative sedative dosing, two other variables-use of preoperative oral sedation and postoperative nausea/emesis-significantly lengthened recovery time (p = 0.0001 for each). Fifteen unintended admissions occurred secondary to nausea, prolonged drowsiness, or pain control needs. Conscious sedation is an effective anesthetic choice for routine plastic surgical procedures, many of which would commonly be performed under general anesthesia. In our experience with a carefully structured and controlled conscious sedation protocol, the technique has proven to be safe and effective. This analysis of outcome parameters identified two important and potentially avoidable causes of recovery delay following conscious sedation-oral premedication and nausea/emesis. Nausea and emesis were particularly problematic in that they were responsible for 11 of 15 (73 percent) unintended admissions. Preoperative sedation is valuable in certain circumstances, and its use is not discouraged; however, its benefits must be weighed against its unwanted effects, which can include a prolongation of recovery.

Combined arterial reconstruction and free tissue transfer for limb salvage.

PURPOSE: Lower-extremity arterial anatomy that is insufficient for successful vein bypass grafting and major proximal foot wounds often lead to leg amputation in patients with severe ischemia. Free tissue transfer, which can provide limb salvage in these patients after arterial reconstruction, was studied. METHODS: During a 45-month period, 21 patients who otherwise would have undergone leg amputation were treated with arterial bypass by means of vein grafting and free tissue transfer. Ages of the patients ranged from 40 to 73 years (average, 59 years); 18 of the 21 patients had diabetes mellitus; and all patients except one were men. Arterial reconstruction was performed from the femoral (nine of 21 patients) or popliteal artery (12 of 21 patients) to the posterior tibial (eight patients), dorsalis pedis (five patients), peroneal (three patients), popliteal (one patient), or anterior tibial artery (one patient), or directly to the free flap (three patients). The tissue transferred included latissimus dorsi (five patients), rectus abdominus (five patients), omentum (five patients), gracilis (two patients), radial forearm flaps (three patients), and a scapular flap (one patient). Foot defects were debrided, including the appropriate toe or transmetatarsal amputation, covered with the transferred flap, and then split-thickness skin grafted. Arterial flow for all flaps was through the vein grafts, with direct arterial anastomosis and with venous outflow through adjacent tibial veins. RESULTS: All 21 procedures were successful initially, without operative mortality, but three failed within 4 weeks because of uncontrolled infection (two) or embolization from a remote site (one) and required below-knee amputation. Grafts remained patent in 18 procedures, and follow-up of this cohort ranged from 1 to 45 months (mean, 13.3 months). Two patients died, one after 4 months and one after 6 months, of unrelated illness; at the time of death, they had functioning grafts. The remaining 19 patients are alive. Of these, 15 have patent arterial grafts, all viable free flaps. Thus, limb salvage was accomplished in 18 of 21 (86%) patients who otherwise would have required below-knee amputation. CONCLUSION: Patients destined for leg amputation despite aggressive traditional arterial bypass grafting methods can achieve limb salvage with the additional technique of free tissue transfer.

Flap prefabrication in the head and neck: a 10-year experience.

Tissue neovascularized by implanting a vascular pedicle can be transferred as a "prefabricated flap" based on the blood flow through the implanted pedicle. This technique potentially allows any defined tissue volume to be transferred to any specified recipient site, greatly expanding the armamentarium of reconstructive options. During the past 10 years, 17 flaps were prefabricated and 15 flaps were transferred successfully in 12 patients. Tissue expanders were used as an aid in 11 flaps. Seven flaps were prefabricated at a distant site and later transferred using microsurgical techniques. Ten flaps were prefabricated near the recipient site by either transposition of a local vascular pedicle or the microvascular transfer of a distant vascular pedicle. The prefabricated flaps were subsequently transferred as island pedicle flaps. These local vascular pedicles can be re-used to transfer additional neovascularized tissues. Common pedicles used for neovascularization included the descending branch of the lateral femoral circumflex, superficial temporal, radial, and thoracodorsal pedicles. Most flaps developed transient venous congestion that resolved in 36 to 48 hours. Venous congestion could be reduced by incorporating a native superficial vein into the design of the flap or by extending the prefabrication time from 6 weeks to several months. Placing a Gore-Tex sleeve around the proximal pedicle allowed for much easier pedicle dissection at the time of transfer. Prefabricated flaps allow the transfer of moderate-sized units of thin tissue to recipient sites throughout the body. They have been particularly useful in patients recovering from extensive burn injury on whom thin donor sites are limited.

The clinical outcome of abdominoplasty performed under conscious sedation: increased use of fentanyl correlated with longer stay in outpatient unit.

The objective of this study was to present data supporting the effectiveness of performing mini and full abdominoplasties under conscious sedation with local anesthesia. The authors performed 20 such operations between 1994 and 1996, using a combination of midazolam (Versed) and fentanyl instead of general anesthesia (without an anesthesiologist or nurse anesthetist present). At 5- to 10-minute intervals, the surgeon would order the injection of 1 cc (1 mg/ml) of midazolam and 1 cc (50 microg/ml) of fentanyl. The amount and the interval varied based on the patient's level of sedation. Blood pressure, oxygen saturation, and the patient's response to verbal and physical stimuli were used to assess the sedation level. Average operating time was 147.5 minutes, and mean length of stay in the outpatient recovery room was 235.5 minutes. The average amounts of midazolam and fentanyl used were 9.4 mg (6 to 12.5 mg) and 532 microg (300 to 800 microg), respectively. The average age of patients in this group was 41.7 years (28 to 63 years). Nineteen patients were discharged the same day. There were no surgical complications and no complication related to the sedation (such as respiratory or cardiac compromise). The average follow-up of these patients was 1.2 years (range, 3 to 21 months). Correlation coefficient rates and regression rates were calculated. The longer the procedure, the more midazolam was used intraoperatively (r = 0.5, p = 0.03). However, there was no correlation between the length of the procedure and the amount of fentanyl used. Rather, there was a positive correlation demonstrating that patients who received more fentanyl stayed longer in the outpatient recovery area after surgery (r = 0.6, p < 0.01). The age of the patients and the amount of midazolam did not correlate with how fast they went home from the outpatient area. In conclusion, full and mini abdominoplasties can be performed safely using conscious sedation without compromising patient care or surgical outcome. Second, the survey revealed that patient satisfaction with these procedures performed under conscious sedation was very high. Third, the increased use of fentanyl, not midazolam, resulted in a longer stay in the outpatient unit after surgery. Nausea is a known side effect of narcotic analgesics, and it correlated with a higher dose of fentanyl administration in the patients. The authors are now routinely administering a dose of either droperidol or odansetron (Zofran) preoperatively (both are antiemetics). Previously, the ratio of midazolam and fentanyl injection was 1:1 every 5 to 10 minutes, but now it is 2: 1 to 4: 1 every 5 to 10 minutes (a smaller dose of fentanyl is administered). The conscious sedation technique should be an option for patients and plastic surgeons in academic and community hospital settings if they desire.

Percutaneous drainage of subcapsular splenic hematoma: an experimental model in dogs.

Preservation of the spleen in patients with posttraumatic subcapsular hematoma is still controversial. To determine the best therapeutic approach for this type of splenic injury, we designed an experimental model of subcapsular hematoma of the spleen in dogs. A total of 23 subcapsular hematomas were caused in 19 dogs, which were followed both clinically and ultrasonographically for 12 weeks. Fifty-seven per cent of the hematomas resolved spontaneously; those that persisted (43%) were aspirated percutaneously with ultrasound guidance, after which they were all resolved. Our results support a conservative approach. When the hematoma does not resolve spontaneously, percutaneous ultrasound-guided aspiration may be considered.

Anti-inflammatory mystixin peptides inhibit plasma leakage without blocking endothelial gap formation.

Mystixins are synthetic peptides that inhibit plasma leakage after tissue injury. We sought to determine the mechanism of the antileakage effect of mystixins, with particular reference to the formation of endothelial gaps in postcapillary venules. Intravenous administration of mystixin-7, a prototype heptapeptide (p-anisoyl-Arg-Lys-Leu-Leu-D-Thi-Ile-D-Leu-NH2), decreased Evans blue leakage induced by substance P (5 microg/kg i.v.) with an ED50 (95% confidence limits) of 130 (76-211) microg/kg in trachea and 52 (27-100) microg/kg in skin of anesthetized F344 rats. Leakage was decreased without a reduction in the number or size of endothelial gaps, visualized by silver deposits after silver nitrate staining. The number of silver deposits per tracheal endothelial cell was 11.4 +/- 0.2 (mean +/- S.E.) after vehicle pretreatment vs. 13.0 +/- 0.8 after mystixin-7 pretreatment (100 microg/kg i.v.). Silver deposit diameter was unchanged at 1.4 +/- 0.1 micron. Mean arterial blood pressure dropped by a maximum of 38% from baseline for approximately 10 min after mystixin-7 (100 microg/kg i.v.), then recovered to a plateau at about 13% below baseline. The antileakage effect of mystixin-7 pretreatment in vivo was also demonstrated in aldehyde-fixed vessels perfused in situ with Evans blue at constant flow (skin, 79% reduction; trachea, 49% reduction), which suggests that mystixin can reduce leakage independent of its hypotensive effect. We conclude that the antileakage effect of mystixin does not depend on reducing the number or size of endothelial gaps, but instead could be caused by residual hypotension, which reduces the negative interstitial fluid pressure toward zero, or clogging of endothelial gaps.

Decreased expression of CD73 (ecto-5'-nucleotidase) in the CD8+ subset is associated with zinc deficiency in human patients.

We used flow cytometry to observe the changes in T cell populations resulting from zinc deficiency in subjects with sickle cell anemia (SCA) and in healthy human volunteers without SCA. Zinc deficiency was associated with significant decreases in cellular zinc concentration, CD4+/CD8+ ratio, and percentage of CD73+ cells in the CD8+ population. The decrease in the percentage of CD73+ cells in the CD8+ subset was significantly correlated with lymphocyte zinc concentration and was accompanied by essentially no change in the percentage of CD11b+ cells in the CD8+ subset. Daily oral zinc supplementation in nine zinc-deficient human volunteers (25 mg elemental zinc) and in seven zinc-deficient SCA subjects (50 mg elemental zinc) resulted in increases in the absolute lymphocyte count and significant increases in the CD4+/CD8+ ratio and in the percentage of CD73+ cells in the CD8+ subset. In zinc-supplemented subjects, the increase in the percentage of CD73+ cells was accompanied by a significant decrease in the percentage of CD11b+ cells in the CD8+ subset. Changes in the CD4+/CD8+ and CD73+/CD11b- cell ratios in the CD8+ subset after treatment may provide a useful diagnostic criterion for zinc deficiency in humans.

Expression of complement regulatory proteins on fetal blood cells in utero.

Since the fetus is semiallogenic to the mother, mechanisms have evolved to protect fetal tissue from the maternal immune response. Among these mechanisms is the expression of cell-surface complement regulatory proteins at the maternal-fetal interface. However, beginning in the third trimester, fetal blood cells are exposed to actively-transported IgG antibody. Thus, we speculated that fetal blood cells would require expression of one or more complement regulators by the early third trimester. Using flow cytometry and Western blots, we have demonstrated the presence of three important complement regulatory proteins in the circulating blood cells of human fetuses. These findings are consistent with the putative biological role of the cell-surface complement regulatory proteins.