Longitudinal study of the frequency of cytotoxic T cell precursors in kidney allograft recipients

Clonal deletion or inactivation of donor-specific alloreactive cells are important mechanisms that are believed to account for acquired immune tolerance in allograft recipients. Serial assessment of precursor cytotoxic T lymphocyte frequencies (CTLpf) by limiting dilution analysis (LDA) provides information at the clonal level on changes in the alloimmune response of graft recipients. We performed a longitudinal study of 15 cadaveric kidney recipients before and every 3 months throughout the first year after transplantation (Tx). Pre-Tx values of donor CTLpf showed high interindividual variability without a predictive value for the clinical outcome. All patients with well functioning kidneys had decreased CTLpf at 3 months post-Tx in comparison with pre-Tx values. This decrease was donor-specific in four patients and was permanent in two cases throughout the study. Most patients presented decreased anti-donor CTLpf values from 6 to 9 months, whereas a partial recovery of donor CTLpf was observed in three patients. Reversible acute rejection was diagnosed in three patients, and it was associated with a marked increase in anti-donor CTLpf, returning to pre-Tx values by 9 months post-Tx. In addition, one patient with chronic rejection displayed a transient increase in CTLpf 6 months after Tx. The results of this sequential study indicate the establishment of a state of either hyporesponsiveness or functional clonal inactivation, transient or permanent, which could facilitate allograft acceptance.     

Corticotropin and cortisol response to maximal exercise testing in central diabetes insipidus

BACKGROUND: It is known that arginine vasopressin (AVP) has a stimulatory effect on corticotropin (adrenocorticotropic hormone; ACTH) and cortisol secretion especially during stress. The present study was designed to investigate the effect of stress on ACTH and cortisol levels in patients with central diabetes insipidus (DI) with endogenous AVP deficiency receiving AVP therapy, and to determine whether these children need steroid replacement during stress. METHODS: Seven patients with a median age of 12 years (range 7-13 years) with idiopathic central DI on appropriate Desmopressin (DDAVP) therapy (group 1) and seven healthy controls with a median age of 15 years (range 13-20 years; group 2) were included in the study. Acute stress was produced in all children by treadmill exercise, assessed by maximal oxygen consumption and heart rate. ACTH and cortisol levels were determined before and after exercise. RESULTS: In group 1, median ACTH level after exercise (28.3 pg/mL) was not different from the median value (24.0 pg/mL) before exercise. However, median cortisol level (10.5 microg/dL) was significantly increased (14.9 microg/dL; P < 0.05) with exercise. In group 2, cortisol (median 9.3 microg/dL) and ACTH levels (median 6.3 pg/mL) were significantly increased after exercise (15 mug/dL and 13.6 pg/mL, respectively; P < 0.05). There was no significant difference between the groups with respect to cortisol levels before and after exercise, but the stimulated ACTH levels after exercise were higher in patients with DI than in the controls (P < 0.05). A positive correlation was observed between total daily DDAVP dose and cortisol level after exercise (r(s)= 0.786, P < 0.05). CONCLUSIONS: Cortisol response during acute stress is normal in children with DI and these patients do not need extra steroid treatment during stress. In contrast, the normal cortisol response obtained by increased ACTH levels in these patients indicates an increased sensitivity of corticotroph cells.     

Virtual reality digital surgical planning for jaw reconstruction: a usability study

Background

Digital surgical planning (DSP) has revolutionized the preparation and execution of the management of complex head and neck pathologies. The addition of virtual reality (VR) allows the surgeon to have a three-dimensional experience with six degrees of freedom for visualizing and manipulating objects. This pilot study describes the participants experience with the first head and neck reconstructive VR-DSP platform.

Methods

An original VR-DSP platform has been developed for planning the ablation and reconstruction of head and neck pathologies. A prospective trial utilizing this platform involving reconstructive surgeons was performed. Participants conducted a simulated VR-DSP planning session, pre- and post-questionnaire as well as audio recordings allowing for qualitative analysis.

Results

Thirteen consultant reconstructive surgeons representing three surgical backgrounds with varied experience were recruited. The majority of surgeons had no previous experience with VR. Based on the system usability score, the VR-DSP platform was found to have above average usability. The qualitative analysis demonstrated the majority had a positive experience. Participants identified some perceived barriers to implementing the VR-DSP platform.

Conclusions

Virtual reality-digital surgical planning is usable and acceptable to reconstructive surgeons. Surgeons were able to perform the steps in an efficient time despite limited experience. The addition of VR offers additional benefits to current VSP platforms. Based on the results of this pilot study, it is likely that VR-DSP will be of benefit to the reconstructive surgeon.     

Leveraging the Experiences of Informal Caregivers to Create Future Healthcare Workforce Options

The objective of this study was gather pilot data from informal caregivers regarding the potential for a training program to assist current or past caregivers in reentering the job market, and thus offering a pathway to economic resilience. In an effort that could foster a sustainable and competent caregiving market to help meet the needs of an aging America, whether training informal caregivers might help them transition into a paid caregiving or other health service role was explored. Caregivers (N = 55) of a chronically or terminally ill family member or friend in a suburban county near Chicago were interviewed. The interview guide addressed household economic effect of illness, emotional burden, and training program interest. Fifty‐six percent of caregivers were interested in training to work outside the home, caring for people in other households, 84% indicated a desire to learn more about health care, and 68% reported a desire to explore job possibilities in health care. Eighty‐two percent were experienced in working with an individual aged 50 and older. Informal caregivers' interest in a training program to bolster their qualifications for a role in the healthcare workforce, including the option of a formal caregiver position, supports the demand for such a program. Considering the need for healthcare workers to serve the growing elderly population and the desire of informal caregivers to find gainful employment, these informal caregivers could provide the impetus to invest in informal caregiver training.     

Effect of carnitine supplementation on cardiac function in hemodialyzed children

Thirteen carnitine-deficient children (mean age, 16.1 ±2.56 years) on a three-times-weekly hemodialysis program for at least 1 year, and 11 healthy age matched children were involved in the study. All the patients had stable blood pressure and hemoglobin (Hb) levels with a maintenance dose of erythropoetin and none were digitalized. The total carnitine (TC) and free carnitine (FC) plasma levels were sampled prior to hemodialysis (HD) before and after 3 months of carnitine supplementation. A free carnitine (FC) to acylcarnitine (AC) ratio less than 4 was defined as carnitine deficiency. Intravenous L-carnitine was injected at a dose of 20–4.0 mg/kg three times weekly at the end of each dialysis session for a 3-month period. Echocardiographic examination was performed the day following HD, before and after carnitine treatment. Systolic and diastolic functions of the left ventricle, including the ejection fraction, were measured. Almost all the parameters were significantly different in controls and hemodiaiyzed patients. In carnitine-deficient hemodiaiyzed patients. 3 months of L-carnitine supplementation resulted in a significant increase in blood carnitine levels and the FC/AC ratio, but this was not associated with any significant improvement of cardiac function. Furthermore no significant changes were observed in plasma triglycerides, total cholesterol or other lipoprotein parameters before or after carnitine supplementation. Although there was a moderate increase in mean hematocrit (Hct) and Hb levels, these also did not reach statistically significant levels. These results suggest that the 3 months of carnitine supplementation is not sufficient to ameliorate cardiac function or increase Hb levels in children.     

The self-reported oral health status and behaviors of adults who are deaf and blind

This qualitative study explored perceived oral health, felt need, oral health knowledge and behaviors, and utilization of dental services among a community of deaf and blind adults in Toronto, Canada. Seven adults participated in in depth interviews facilitated by intervenors skilled in communication with people who are deaf and blind. Subjects reported that their oral health was good, however oral health knowledge was poor and daily oral hygiene practices were minimal. Few subjects had ever received dental health education and were largely unaware of how to prevent dental disease. A subsidized dental program enabled subjects to have regular dental visits, though they were concerned about the costs of more complex dental treatment not covered by the program. They also worried about finding an alternative source of care once their eligibility for the program ceased at the age of 65. The presence of the subsidized sympathetic dental program and the facilitative role of intervenors promoted utilization of dental care for many of the subjects who participated in this study. There is a clear need to develop appropriate dental health education programs for this group of people, which would harness the support of the community of deaf and blind people and their intervenors. The interventions need to be sensitive and appropriate for the individual's level of impairment.