Induction of resistance to diabetes in non-obese diabetic mice by targeting CD44 with a specific monoclonal antibody

Inflammatory destruction of insulin-producing beta cells in the pancreatic islets is the hallmark of insulin-dependent diabetes mellitus, a spontaneous autoimmune disease of non-obese diabetic mice resembling human juvenile (type I) diabetes. Histochemical analysis of diabetic pancreata revealed that mononuclear cells infiltrating the islets and causing autoimmune insulitis, as well as local islet cells, express the CD44 receptor; hyaluronic acid, the principal ligand of CD44, is detected in the islet periphery and islet endothelium. Injection of anti-CD44 mAb 1 hr before cell transfer of diabetogenic splenocytes and subsequently on alternate days for 4 weeks induced considerable resistance to diabetes in recipient mice, reflected by reduced insulitis. Contact sensitivity to oxazolone was not influenced by this treatment. A similar antidiabetic effect was observed even when the anti-CD44 mAb administration was initiated at the time of disease onset: i.e., 4-7 weeks after cell transfer. Administration of the enzyme hyaluronidase also induced appreciable resistance to insulin-dependent diabetes mellitus, suggesting that the CD44-hyaluronic acid interaction is involved in the development of the disease. These findings demonstrate that CD44-positive inflammatory cells may be a potential therapeutic target in insulin-dependent diabetes.     

Delays to Care in Pediatric Lupus Patients: Data From the Childhood Arthritis and Rheumatology Research Alliance Legacy Registry

Objective

Prompt treatment for lupus is important to prevent morbidity. A potential barrier to early treatment of pediatric lupus is delayed presentation to a pediatric rheumatologist. To better understand factors contributing to delayed presentation among pediatric lupus patients, we examined differences in demographic and clinical characteristics of lupus patients within the Childhood Arthritis and Rheumatology Research Alliance (CARRA) Legacy Registry with regard to time between symptom onset and presentation to a pediatric rheumatologist.

Methods

We analyzed data from 598 CARRA Legacy Registry participants for differences between those who presented early (within <1 month of symptom onset), between 1–3 months (typical presentation), with moderate delays (3–12 months), and with severe delays (≥1 year). Factors associated with early presentation, moderate delay, and severe delay were determined by multinomial logistic regression.

Results

Forty‐four percent of patients presented early, while 23% had moderate delays and 9% had severe delays. Family history of lupus, absence of discoid rash, and location in a state with a higher density of pediatric rheumatologists were associated with earlier presentation. Younger age, low household income (<$25,000 per year), and a family history of lupus were associated with severe delay.

Conclusion

Delays to care ≥1 year exist in a notable minority of pediatric lupus patients from the CARRA Legacy Registry. In this large and diverse sample of patients, access to care and family resources played an important role in predicting time to presentation to a pediatric rheumatologist.

     

Inverse correlation between coronary and retinal blood flows in patients with normal coronary arteries and slow coronary blood flow

Background

The “Slow Coronary Flow” (SCF) phenomenon in the presence of angiographically normal coronaries is attributed to microvascular and endothelial dysfunction. The microcirculation can be non-invasively assessed by measuring retinal blood flow velocity.The aim of the present study was to evaluate the efficacy of the “Retinal Functional Imager” (RFI) device as a noninvasive method of diagnosing patients with slow coronary flow.

Methods

Coronary blood flow velocity assessed by corrected TIMI Frame Count and retinal arterioles blood flow assessed by RFI were measured in 28 consecutive patients with normal coronary arteries. The patients were divided into 2 groups: a slow coronary flow (SCF) and a normal coronary flow (NCF) groups.

Results

Inverse correlation was found between retinal and coronary blood flows so that higher retinal arterial flow velocity was observed in the SCF group (3.8 ± 1.1 mm/s vs. 2.9 ± 0.61 mm/s, respectively, p = 0.022). RFI provided 73% sensitivity and 77% specificity for diagnosing SCF using ROC analysis. Additionally, patients with SCF had higher values of serum LDL cholesterol (104.7 ± 18.93 mg/dl vs. 81.55 ± 14.62 mg/dl in NCF, p = 0.005), Glucose (96.9 ± 23.0 mg/dl vs. 83.55 ± 9.7 mg/dl in NCF, p = 0.024), and lower percentage of statin consumption (40.0% vs. 76.9% in NCF, p = 0.049).

Conclusions

Slow coronary blood flow can be non-invasively diagnosed with Retinal Functional Imager. Patients with normal coronary arteries and slow coronary blood flow have high retinal arteriolar blood flow. Early non-invasive diagnosis of SCF might help detect individuals who are at higher risk to develop coronary atherosclerosis, and to provide them with early preventive measures.     

Newborn Screening for SCID in New York State: Experience from the First Two Years

Purpose

To describe the process and assess outcomes for the first 2 years of newborn screening for severe combined immunodeficiency (SCID NBS) in New York State (NYS).

Methods

The NYS algorithm utilizes a first-tier molecular screen for TRECs (T-cell receptor excision circles), the absence of which is indicative of increased risk of immunodeficiency.

Results

During the first 2 years, 485,912 infants were screened for SCID. Repeat specimens were requested from 561 premature and 746 non-premature infants with low or borderline TRECs. A total of 531 infants were referred for diagnostic evaluation leading to identification of 10 infants with SCID and 87 with a clinically significant non-SCID abnormality based on flow cytometry or CBC results (positive predictive value 20.3 %). Nine infants were diagnosed with typical SCID and one with leaky SCID. SCID diagnoses included two patients with adenosine deaminase deficiency, three patients with typical and one with leaky IL2RG-related SCID, one patient with IL7Rα-related SCID, and three cases of typical SCID, etiology unknown. TRECs were undetectable in eight of the nine babies with typical SCID. Infants with other non-SCID conditions included 27 patients with a syndrome that included T-cell impairment, 18 of which had DiGeorge syndrome. Seventeen infants had T-cell impairment secondary to another clinically significant condition, and 13 were classified as ‘other’. Among 30 infants classified as idiopathic T-cell lymphopenia, 11 have since resolved, and the remainder continues to be followed. One infant with undetectable TRECs had normal follow-up studies. Molecular studies revealed the presence of two changes in the infant’s DNA.

Conclusions

Overall, ten infants with SCID were identified during the first 2 years of screening in NYS, yielding an incidence of approximately 1 in 48,500 live births, which is consistent with the incidence observed by other states screening for SCID. The incidence of any clinically significant laboratory abnormality was approximately 1 in 5,000; both estimates are higher than estimates prior to the onset of newborn screening for SCID. Improvements to the NYS algorithm included the addition of a borderline category that reduced the proportion of infants referred for flow cytometric analysis, without decreasing sensitivity. We identified a large number of infants with abnormal TRECs and subsequent idiopathic T-cell lymphopenia. Long-term follow-up studies are needed to determine the prognosis and optimal treatment for this group of patients, some of whom may present with previously unrecognized, transient lymphopenia of infancy.     

The protective effect of interferon against natural killing activity is not mediated via the expression of class I MHC antigens

Natural-killer cell mediated cytotoxicity (NK-CMC) is modulated by interferons both at the effector cell and at the target cell levels. Pretreatment of effector cells with interferon increases their cytotoxicity while pretreatment of target cells with interferons decreases their sensitivity to NK-CMC. Interferons are inducers of several genes including those of the major histocompatibility complex (MHC) and several earlier studies have established a circumstantial correlation between induction of class I MHC gene products and induction of resistance to NK-CMC. In the present study we demonstrate that interferon-alpha renders Daudi cells resistant to NK-CMC without inducing the surface expression of class I MHC antigens. Therefore we suggest that these two phenomena are independent responses to interferon treatment.     

Holmium YAG laser-assisted osteotomies in plastic and reconstructive surgery: a preliminary report.

An Omnipulse holmium-yttrium aluminum garnet (YAG) laser was used to assist in the harvesting of outer table or split calvarial bone grafts in cadaver skulls. Two- or 4-mm depth and 0.55-mm width holes in the outer cortex of cadaveric calvarium were formed without apparent gross periosteal or bony injury. Osteotomes were then used to shave or split calvarial grafts by connecting the 2- and 4-mm depth holes, respectively. The procedure was efficient as well as precise. We believe that this method of bone graft harvesting may have the added benefit of safety by decreasing the incidence of inadvertent dural penetration. This study will lead to further analysis of the potential use for additional bony work with the Omnipulse holmium-YAG laser.