Comparative effects of plateletderived growth factor-BB and insulin-like growth factor-I, individually and in combination, on periodontal regeneration in Macaca fascicularis

Platelet-derived growth factor (PDGF) and insulin-like growth factor I (IGF-I) in combination have previously been shown to enhance periodontal regeneration. The objective of this study was to further characterize the biological effects of this combination of growth factors in non-human primates and compare the effects to those of each growth factor individually. Ligature-induced periodontitis was initiated in 10 cynomolgus monkeys. After periodontal lesions were established, surgery was performed, and either a methylcellulose gel vehicle or vehicle containing 10 μg each of either PDGF-BB, IGF-I or both PDGF-BB and IGF-I was applied to exposed root surfaces. Biopsies were taken 4 and 12 wk after treatment and the extent of periodontal regeneration was assessed by histomorphometry. At both 4 and 12 wk vehicle-treated lesions generally revealed minimal osseous defect fill (ODF) (8.5±2.1% and 14.5±5.7%, respectively) and new attachment (NA) (34.1±5.2% and 26.6±10.5%, respectively). IGF-I treatment did not significantly alter healing compared to vehicle in any parameter at both 4 and 12 wk. PDGFBB-treated sites exhibited significant (p<0.05) regeneration of NA (69.6±12.0%) at 12 wk; trends for PDGF-BB treatment effect were also observed in other parameters at 4 and 12 wk. although these increases were not statistically significant. Treatment with PDGF-BB/IGF-I resulted in 21.6±5.1 % and 42.5±8.3% ODF at 4 and 12 wk, respectively, and 64.1±7.7% and 74.6±7.4% NA at 4 and 12 wk, respectively (all significantly greater than vehicle, p<0.05). The results from this study demonstrated that: 1) IGF-1 alone at the dose tested did not significantly alter periodontal wound healing; 2) PDGF-BB alone significantly stimulated NA, with trends of effect on other parameters; and 3) the PDGF-BB/IGF-I combination resulted in significant increases in NA and ODF above vehicle at both 4 and 12 wk.     

Recombinant human interferon alpha increases oestrogen receptor expression in human breast cancer cells (ZR-75-1) and sensitizes them to the anti-proliferative effects of tamoxifen

Exposure of ZR-75-1 human breast cancer cells for 48 h to human recombinant interferon alpha (IFN alpha) resulted in increased expression of oestrogen receptors as measured in a whole cell binding assay. This effect was inversely proportional to dose being significant following treatment with 10-100 IU IFN ml-1 and was only observed at a low initial cell plating density. The extent of the increase in oestrogen receptor levels ranged from 1.2- to 7.2-fold following treatment with 10 IU IFN ml-1. No increase in progesterone receptor expression was observed under the same experimental conditions. Concentrations of IFN which increased oestrogen receptor levels had no effect on cell proliferation. IFN (500 IU ml-1) inhibited cell proliferation and the combination of this treatment with tamoxifen (2 microM) had a greater anti-proliferative effect than either drug alone although there was no evidence of synergism. However, a 5-day pretreatment of cells with IFN (10 IU ml-1) markedly sensitised them to the growth-inhibiting effect of a subsequent 6-day exposure to tamoxifen.     

Accurate patient history contributes to differentiating diabetes insipidus: a case study.

This case study highlights the important contribution of nursing in obtaining an accurate health history. The case discussed herein initially appeared to be neurogenic diabetes insipidus (DI) secondary to a traumatic brain injury. The nursing staff, by reviewing the patient's health history with his family, discovered a history of polydipsia and long-standing lithium use. Lithium is implicated in drug-induced nephrogenic DI, and because the patient had not received lithium since being admitted to the hospital, his treatment changed to focus on nephrogenic DI. By combining information from the patient history, the physical examination, and radiologic and laboratory studies, the critical care team demonstrated that the patient had been self-treating his lithium-induced nephrogenic DI and developed neurogenic DI secondary to brain trauma. Thus successful treatment required that nephrogenic and neurogenic DI be treated concomitantly.     

Genotype/phenotype of familial pancreatic cancer.

It is estimated that 5% to 10% of pancreatic cancer cases are attributable to hereditary factors. We believe that the number of cases that are genetic in etiology are even greater, however, based not on a classic autosomal dominant pattern of inheritance but rather when one takes into account low-penetrant inherited susceptibility factors. There is also a growing recognition that the development of pancreatic cancer in pancreatic cancer-prone families is dependent not only on genetic variables but on nongenetic factors. The aim of this article is to review the challenges in identifying pancreatic cancer-prone families and how environmental factors interact with genetic factors in these families.     

GLUT1 and GLUT8 in endometrium and endometrial adenocarcinoma.

Glucose is provided to cells by a family of glucose transport facilitators known as GLUTs. These transporters are expressed in a tissue specific manner and are overexpressed in many primary tumors of these tissues. Regulation of glucose transport facilitator expression has been demonstrated in endometrial tissue and endometrial adenocarcinoma. The following experiments were conducted to quantify and localize the expression of GLUT1 and GLUT8 in benign endometrium and compare this expression to endometrial cancer. Endometrial tissue samples were obtained from random hysterectomy specimens of patients with benign indications for surgery and endometrial cancer. Immunoblot and immunolocatization studies were performed using GLUT1 and GLUT8 specific antisera. Endometrial samples from 65 women who had undergone hysterectomy were examined (n=38 benign, n=27 malignant). A 44 and a 35.4 kDa immunoreacive species was demonstrated in endometrium and endometrial cancer for GLUT1 and GLUT8, respectively. Upregulation of GLUT1 expression was demonstrated with increasing grade of tumors (P<0.002). GLUT8 expression was increased in all tumor subtypes compared to atrophic endometrium (P<0.001). Apical localization by GLUT1 and GLUT8 was demonstrated in endometrial glands. GLUT1 and GLUT8 demonstrated diffuse intracellular localization in the cancer subtypes. GLUT1 and GLUT8 are expressed in both human endometrium and endometrial cancer. There appears to be a step-wise progression in GLUT1 and GLUT8 expression as tumor histopathology worsens. GLUT1 and GLUT8 may be important markers in tumor differentiation, as well as providing energy to rapidly dividing tumor cells.     

A Comparative Study of the Percutaneous versus Intraoral Technique for Mental Nerve Block

Objective: Mental nerve block is frequently used to aid repair of facial lacerations; both percutaneous and intraoral approaches to blocking this nerve are used, but have never been compared. The authors compared the two techniques for pain of administration and effectiveness of anesthesia. Methods: A prospective, randomized, single-blind, crossover study was conducted using ten healthy volunteers aged 22 to 33 years. Patients having prior experience with mental nerve blocks, lidocaine allergy, active oral/facial infection, or previous facial fractures were excluded. Bilateral mental nerve blocks were done using intraoral technique on one side and percutaneous technique on the other. Both techniques were used by the same investigator and were carried out with 27-gauge needles and 2.5 mL of 2% buffered lidocaine at room temperature injected over 20 seconds. The oral mucosa was topically anesthetized with viscous lidocaine for 1 minute prior to intraoral injection. The orders of the blocks and sides of the face anesthetized were randomized. Subjective and objective pain (visual-analog scale), efficacy (anesthesia of lower lip), time to onset, and duration of anesthesia were evaluated. Results: The intraoral technique was subjectively less painful than the percutaneous approach in nine of ten subjects (p = 0.02). Scores on the visual-analog pain scale were significantly lower for the intraoral technique (p = 0.03). Intraoral injection produced lower-lip anesthesia in 10/10 subjects versus 7/10 for percutaneous (p = 0.25). Times to onset (approximately 1–2 minutes) and durations of anesthesia (approximately one hour) were similar for the two techniques. Conclusion: The intraoral approach to the mental nerve block with adjunctive topical anesthesia was subjectively and objectively less painful than the percutaneous approach without adjunctive anesthesia. While the intraoral approach had a greater efficacy of lower-lip anesthesia and a longer duration of action, these differences were not statistically significant.     

Tolerance-like attenuation to contingent and noncontingent cocaine-induced elevation of extracellular dopamine in the ventral striatum following 7 days of withdrawal from chronic treatment

Time-dependent changes in mesolimbic dopamine (DA) function are believed to play a role in behavioral sensitization and drug craving experienced during withdrawal from chronic cocaine administration. The present study utilized intravenous (IV) cocaine self-administration coupled with intracranial microdialysis in rats to investigate time dependent changes during withdrawal from chronic cocaine exposure. Following 2 weeks of IV cocaine self-administration, rats were allowed contingent access to cocaine at 1 and 7 days of withdrawal while extracellular levels of DA were measured from the ventral striatum. A second group of animals received yoked, noncontingent cocaine for 2 weeks and were then administered noncontingent cocaine on days 1 and 7 of withdrawal. In addition, a third group of animals received 2 weeks of yoked saline followed by noncontingent cocaine 1 day after withdrawal. There were no significant differences between groups for the overall cocaine dosage or temporal pattern of infusions on days 1 and 7 of withdrawal. Basal extracellular DA concentrations did not differ between any treatment groups at either withdrawal time. Extracellular DA levels were increased throughout the session on both days; however, the increases at day 7 were significantly less than day 1 for both contingent and noncontingent conditions. DA overflow on day 1 did not differ between animals receiving chronic yoked cocaine or saline. These results suggest that tolerance-like attenuation to the DA-elevating effects of cocaine is not apparent early in withdrawal, but does develop by later time points. DA release in the ventral striatum may not be directly related to cocaine self-administration following withdrawal, since DA levels were attenuated after 7 days of withdrawal while responding for cocaine was unaltered.     

Thrombosis of the inferior vena cava by seminoma

We report a case of metastatic seminoma that caused thrombosis and obstruction of the inferior vena cava. The pathogenesis of this rare clinical entity is discussed. The diagnostic studies for detection of vena caval thrombosis and clinical management strategies are reviewed.