Cytokines and cell signalling in the periodontium

A large number of potential regulatory mechanisms have been described which may be involved in the control of cell function in the periodontium. In this review, soluble effector molecules which may regulate normal cell turnover and which may control the maintenance of the per-iodontal space are considered. There is evidence for the involvement of growth factors including EGF, PDGF, FGFs, IGF I & II and TGFβ in these processes. The role of bone morphogenetic proteins (BMPs) in periodontal turnover is of considerable interest as they appear to be able to regulate all stages of this process from specifying cell commitment to regulating differentiated cell function.
Empirical evidence suggests the importance of mechanical stimulation in controlling the maintenance of the periodontal ligament space. The wide range of effects of mechanical stimulation are briefly reviewed and the central role of prostaglandins is considered. Recent evidence suggests the involvement of nitric oxide (NO) in the regulation of mineralised tissue function, and the potential role of NO in maintenance of the ligament space is considered. Further studies are required which address the interactions between all of these mechanisms in order to determine the key factors which may control periodontal cell function. For the future an understanding of these interactions has the potential to lead to important clinical developments in periodontal and orthodontic therapy.     

Psychosocial impact of Von Hippel–Lindau disease: levels and sources of distress

Lammens CRM, Bleiker EMA, Verhoef S, Hes FJ, Ausems MGEM, Majoor‐Krakauer D, Sijmons RH, Luijt van der RB, Ouweland van den AMW, Van Os Tam, Hoogerbrugge N, Gomez‐Garcia EB, Dommering CJ, Gundy CM, Aaronson NK. Psychosocial impact of von Hippel–Lindau disease: levels and sources of distress. Von Hippel–Lindau disease (VHL) is a hereditary tumor susceptibility syndrome, characterized by an increased risk of developing multiple benign and malignant tumors at various sites and ages with limited preventive options. This study evaluates the prevalence of distress among VHL family members and factors associated significantly with such distress. Forty‐eight families with a VHL mutation were identified via the nine family cancer clinics in the Netherlands. In total, 171 family members (carriers, 50% at‐risk, non‐carriers) were approached, of whom 123 (72%) completed a self‐report questionnaire. Approximately 40% of the VHL family members reported clinically relevant levels of distress, approaching 50% among the carriers and, possibly even more striking, 36% among the non‐carriers. Having lost a first degree relative due to VHL during adolescence (OR 11.2; 95% CI 1.4–86.9) was related significantly to heightened levels of distress. Approximately, only one‐third of those who reported heightened levels of distress had received professional psychosocial support. A substantial percentage of family members experience clinically relevant levels of distress. We would recommend the introduction of a procedure for screening for distress in this vulnerable population. Special attention should be paid to those individuals who have lost a close relative due to VHL during adolescence.     

Electrical nerve localization: non-linear relationship between intensity and pulse duration to stimulate a nerve

Objective

When performing a peripheral nerve block, the current allowing local anaesthetic injection is between 0.3 and 0.5 mA. It has never been assessed if such a threshold remains the same whatever be the pulse duration. The aim of this study was to determine the minimal current required to stimulate a nerve while different pulse durations were applied, and to evaluate the importance of the placement of the cutaneous electrode.

Study design

Prospective study.

Patients and methods

One hundred and twenty posterior popliteal sciatic (S), femoral (F), or median (M) nerve blocks performed with a nerve stimulator were included. The minimal current for a clearly visible motor response of the corresponding muscle was recorded with a pulse duration set at 50, 150 and 300 μs. The same procedure was repeated with the electrode sited on the controlateral side, before injection of local anaesthetic.

Results

The mean lowest charge of current required to stimulate a nerve was 24 ± 8 nC at 50 μs. At 150 and 300 μs, it has to be increased by 175 % (42 ± 14 nC) and 280 % (67 ± 23 nC), respectively. No significant difference in the charge required was noted either among S, F, or M, or by changing the cutaneous electrode position. Adequate anaesthesia was noted in all cases.

Conclusion

The relationship between intensity and pulse duration is not linear. Moreover, a low charge of current does not seem to be appropriate with pulse duration equal or superior to 300 μs. The location of the cutaneous electrode does not seem to be important.     

Injectable Materials for the Treatment of Myocardial Infarction and Heart Failure: The Promise of Decellularized Matrices

Cardiovascular disease continues to be the leading cause of death, suggesting that new therapies are needed to treat the progression of heart failure post-myocardial infarction. As cardiac tissue has a limited ability to regenerate itself, experimental biomaterial therapies have focused on the replacement of necrotic cardiomyocytes and repair of the damaged extracellular matrix. While acellular and cellular cardiac patches are applied surgically to the epicardial surface of the heart, injectable materials offer the prospective advantage of minimally invasive delivery directly into the myocardium to either replace the damaged extracellular matrix or to act as a scaffold for cell delivery. Cardiac-specific decellularized matrices offer the further advantage of being biomimetic of the native biochemical and structural matrix composition, as well as the potential to be autologous therapies. This review will focus on the requirements of an ideal scaffold for catheter-based delivery as well as highlight the promise of decellularized matrices as injectable materials for cardiac repair.     

Two cases of Robertsonian translocations in oligozoospermic males and their consequences for pregnancies induced by intracytoplasmic sperm injection

Two case histories are presented documenting structural chromosome abnormalities in infertile males. The abnormalities were detected only after application of intracytoplasmic sperm injection (ICSI) was repeatedly unsuccessful or resulted in an abnormal pregnancy. A mosaic Robertsonian translocation 45,XY,der(13;13)(q10; q10)/46,XY,t(13;13)(p10;p10), der(13p;13p) incompatible with normal offspring was found in a male with extreme oligozoospermia after three subsequent ICSI treatments were unsuccessful and one had resulted in a spontaneous abortion. A second case involved a Robertsonian translocation 45,XY,der(13;14)(q10;q10) which was detected in a male with extreme oligozoospermia after ultrasound abnormalities were found in an ICSI-induced twin pregnancy. Amniocentesis showed an unbalanced 46,XY,+13,der(13;14)(q10;q10) karyotype in one twin and a Robertsonian 45,XX,der(13;14)(q10;q10) karyotype in the other twin. Chromosome analysis of males with abnormal sperm characteristics is advised prior to ICSI.      

Treatment of the male with follicle-stimulating hormone in intrauterine insemination with husband's spermatozoa: a randomized study

We have examined the potential of follicle-stimulating hormone (FSH) therapy for the male to improve pregnancy rates in intrauterine insemination (IUI) with husband's spermatozoa. A prospective randomized trial was performed in 148 couples undergoing IUI because of male subfertility. In the treatment group, 150 IU FSH were administered to the husbands, either i.m. or s.c., three times a week, starting 3 months before the beginning of IUI cycles and maintained until the fifth IUI cycle. In the control group no treatment was given. FSH therapy did not change semen parameters. The pregnancy rate per cycle was 13.47% in the FSH group versus 10.07% in the non-FSH group; the pregnancy rate per woman was 44.38% in the FSH group versus 37.18% in the non-FSH group. Although the pregnancy rate increase was > 30% per cycle and > 20% per woman, statistical significance was not achieved. The cumulative pregnancy rate was 59.20% in the FSH group versus 42.91% in the non-FSH group. The pregnancy rate outside the IUI cycle was 14.70% (10/68) in the FSH group versus 2.5% (2/80) in the non-FSH group, the difference being statistically significant. In conclusion, a non-significant trend towards higher pregnancy rates in IUI was observed in the FSH group.