The cerebellar fastigial nucleus contributes to CO2-H+ ventilatory sensitivity in awake goats

The purpose of this study was to test the hypothesis that an intact cerebellar fastigial nucleus (CFN) is an important determinant of CO(2)-H(+) sensitivity during wakefulness. Bilateral, stainless steel microtubules were implanted into the CFN (N=9) for injection (0.5-10 microl) of the neurotoxin ibotenic acid. Two or more weeks after implantation of the microtubules, eupneic breathing and CO(2)-H(+) sensitivity did not differ significantly (P>0.10) from pre-implantation conditions. Injection of ibotenic acid (50 mM) did not significantly alter eupneic Pa(CO2) (P>0.10). The coefficient of variation of eupneic Pa(CO2) was 4.0+/-0.6 and 3.7+/-0.4% over the 2 weeks before and after the lesion, respectively. CO(2)-H(+) sensitivity expressed as inspired ventilation/Pa(CO2) decreased from 2.15+/-0.17 pre-lesion to 1.58+/-0.26 l/(min mmHg) 3-6 days post-lesion (P<0.02, -27%). There was no significant (P>0.10) recovery of sensitivity between 7 and 10 days post-lesion. The lesion also increased (P<0.05) the day-to-day variability of this index by nearly 100%. When CO(2) sensitivity was expressed as elevated inspired CO(2)/room air V (I), values at 7%, but not 3 and 5% inspired CO(2), were reduced and more variable (P<0.05) after the ibotenic acid injections. We conclude that during wakefulness, the CFN contributes relatively more to overall ventilatory drive at high relative to low levels of hypercapnia.

Corticotropin-releasing hormone skin signaling is receptor-mediated and is predominant in the sebaceous glands

There is increasing evidence that the sebaceous gland expresses receptors for several neuropeptides and is involved in responses to stress. Among them, corticotropin-releasing hormone (CRH) was currently found to be produced also in the skin. In this study, the distribution of CRH, CRH receptors 1 and 2 (CRH-R1 and CRH-R2), and CRH binding protein (CRH-BP) in cultured human (SZ95) sebocytes was further characterized. Moreover, the effects of CRH and CRH-like peptides on proliferation and inflammatory signaling of CRH receptor-expressing SZ95 sebocytes IN VITRO were investigated. Urocortin (Uct), urotensin and sauvagine are recently described members of the family of structurally related CRH-like peptides, whereas Uct shares a 45% homology with CRH. CRH and Uct inhibited SZ95 sebocyte proliferation with CRH also stimulating interleukin-6 (IL-6) and interleukin-8 (IL-8) release from SZ95 sebocytes. However, CRH had no effect on interleukin-1alpha and interleukin-1beta production in these cells. alpha-Helical-CRF, a CRH antagonistic peptide, annulled the CRH effect on SZ95 sebocyte proliferation and interleukin secretion, while the non-peptidic CRH-R1 selective antagonist antalarmin inhibited the increased production of neutral lipids caused by CRH. In conclusion, CRH, and to a lesser extent Uct, may be involved in signaling of stress pathophysiology in the skin. However, further investigations into the downstream effects of CRH and Uct are required to elucidate the mechanism by which these neuropeptides could establish a stress-related pathophysiological condition in the skin.

[High-dose rate brachytherapy for high-risk prostate cancer]

To estimate disease-free survival it is necessary to allocate patients into tumor risk groups: locally advanced prostate carcinoma with extracapsular spread or localized prostate carcinoma of tumor stage T2c or one of the risk factors PSA >20 or Gleason > or =8 apply for the high-risk group. Intermediate-risk carcinomas are those belonging to tumor stage T2b or with PSA >10-20 or Gleason 7. Particularly for patients with intermediate and high-risk disease early PSA relapse is of major interest. This phenomenon could be a consequence of current inadequate imaging of lymph node or bone metastasis or as a consequence subclinical metastatic spread remains undetectable during radical treatment. However, tumor biology itself could lead to the progression of the disease in the high-risk group. As a consequence, risk-adapted therapy is very important in these cases. The applied radiation dose plays an important role in radiotherapy. Several publications have shown that the biochemical relapse correlates with the generally accepted risk factors and the radiation dose. Regarding this, high-quality treatment planning and HDR brachytherapy combined with EBRT (external beam radiation therapy) leads to good treatment results in selected groups. So far in our own experience, HDR brachytherapy in combination with EBRT is a successful form of treatment with few acute and late side effects in the first 42 patients examined. First results concerning to PSA relapse-free time, quality of life, miction, and erectile function are promising.

Lesions in the cerebellar fastigial nucleus have a small effect on the hyperpnea needed to meet the gas exchange requirements of submaximal exercise

The purpose of this study was to test the hypothesis that an intact cerebellar fastigial nucleus (CFN) is necessary for the hyperpnea to meet the gas exchange needs of submaximal exercise. Bilateral stainless steel microtubules were implanted in the cerebellum inside (n = 12) or outside (n = 2) the CFN for injection (0.5 to 10 microl) of the neurotoxin ibotenic acid. All goats had difficulty maintaining normal posture and walking for up to 1 mo after the implantation of the microtubules and again for hours or days after the neurotoxin was injected. Postmortem histology indicated there were 55% fewer living neurons (P < 0.001, n = 9, 3,720 +/- 553 vs. 1,670 +/- 192) in the CFN of the experimental goats compared with a control group of goats. As is typical for goats before implantation of the microtubules, the decrease in arterial Pco(2) from rest during mild and moderate treadmill exercise was 2.0 +/- 0.39 and 3.5 +/- 0.45 Torr, respectively. Implantation of the microtubules did not significantly change this exercise hyperventilation. However, neurotoxic lesioning with 10 mul ibotenic acid significantly (P < 0.05) attenuated the decrease in arterial Pco(2) by 1.3 and 2.8 Torr at the first and second workload, respectively. The modest attenuation of the exercise hypocapnia at both workloads in CFN-lesioned goats suggests that the CFN is part of the control system that enables the ventilatory response to meet the gas exchange requirements of submaximal exercise.

CO2/H+ chemoreceptors in the cerebellar fastigial nucleus do not uniformly affect breathing of awake goats

Our objective in this study was to test the hypothesis that focal acidosis (FA) in the cerebellar fastigial nucleus (CFN) of awake goats arising from global brain acidosis induced by increasing inspired CO2 will increase breathing. FA was created by reverse microdialysis of mock cerebral spinal fluid, equilibrated with 6.4, 25, 50, or 80% CO2 through chronically implanted microtubules (cannula). Dialysis with 6.4% CO2 had no significant effects on any physiological parameters. However, microdialysis at higher levels of CO2 increased pulmonary ventilation (V(I)) in one group of studies and decreased V(I) in a second group and the difference between the groups was significant (t = 9.16, P < 0.001). In one group of studies (n = 8), FA with 50 and 80% CO2 significantly increased (P < 0.05) Vi by 16 and 12%, respectively, and significantly increased (P < 0.05) heart rate by 13 and 9%, respectively. In contrast, in another group of studies (n = 6), FA with 25 and 50% CO2 significantly decreased (P < 0.05) Vi by 7 and 10%, respectively. In this group oxygen consumption was decreased during dialysis with 80% CO2. On the basis of histology, we estimate that the increased and decreased responses were associated with FA primarily in the rCFN and cCFN, respectively. We conclude that there are CO2/H+-sensitive neurons in the CFN that do not uniformly affect breathing. In addition, the significant changes in heart rate and oxygen consumption during FA indicate that the CFN can also influence non-respiratory-related control systems.

[Association between classic cardiovascular risk factors and age-related maculopathy (ARM). Results of the baseline examination of the Münster Aging and Retina Study (MARS)]

BACKGROUND

Epidemiological studies have reported inconsistent associations between cardiovascular risk factors and the occurrence of age-related maculopathy (ARM).

METHODS

In the baseline examination of the Muenster Aging and Retina Study (MARS), we assessed this potential relationship in 1060 subjects who underwent clinical and ophthalmologic examinations. The ARM status was graded according to international standardized classifications.

RESULTS

There were 974 eye pairs available for analysis. Smoking, hypertension, hypercholesterolemia, and a history of myocardial infarction or stroke were found significantly more often in patients with ARM. There were no statistically significant multivariate associations between overweight, diabetes, or a history of myocardial infarction or stroke.

CONCLUSIONS

Our results confirm previous epidemiological studies pointing to a potential role of atherosclerotic processes in the development of ARM.

Visuelle Funktion und Lebensqualität bei Patienten mit altersabhängiger Makulopathie: Ergebnisse der Münsteraner Altern- und Retina-Studie (MARS)

BACKGROUND

The aim of this study was to examine the association between increasing severity of age-related maculopathy (ARM) stages, visual function and quality of life.

METHODS

Using the 25-item version of the National Eye Institute Visual Function Questionnaire (NEI VFQ) in the Münster age and retina study (MARS), 974 patients (normal fundus: n = 208; early ARM: n = 466; late ARM: n = 300) with bilateral gradable fundus photographs were asked about their visual function and quality of life. The NEI VFQ scales with regard to general health, general vision, near vision, distance vision and peripheral vision were assessed. According to the ARM stages, age- and gender-adjusted mean scores were calculated and tested for statistically significant differences.

RESULTS

The perception of general health, general vision, near vision, distance vision and peripheral vision was getting worse with increasing severity of ARM stages. Comparing the maculopathy groups, significant differences in age- and gender-adjusted mean scores were found between patients with late ARM and healthy subjects and patients with late and early ARM. Furthermore, we observed for the dimension general vision a significant difference of the mean score between early ARM and healthy control group [mean score; early ARM: 68.7 (0.7) vs. control group: 72.2 (1.1); p = 0.005].

CONCLUSIONS

The results of the NEI VFQ reflect the clinical expectation of an inverse relation between increasing severity of ARM stages and visual function and quality of life.

Evaluation of insulin-like growth factor II, cyclooxygenase-2, ets-1 and thyroid-specific thyroglobulin mRNA expression in benign and malignant thyroid tumours

OBJECTIVE

We evaluated three markers (insulin-like growth factor II (IGF-II), cyclooxygenase-2 (COX-2) and ets-1) of thyroid growth stimulation and cell transformation together with a thyroid-specific marker (thyroglobulin (Tg)) for their potential to differentiate benign and malignant follicular thyroid neoplasia (FN).

DESIGN AND METHODS

mRNA expression levels were determined by real-time PCR in 100 snap-frozen thyroid samples: 36 benign thyroid nodules with different histology and function (19 cold (CTN) and 17 toxic thyroid nodules (TTN)), 36 corresponding normal thyroid tissues of the same patients, eight Graves' disease (GD) thyroids, 10 follicular thyroid carcinomas (FTC) and 10 papillary thyroid carcinomas (PTC).

RESULTS

Mean IGF-II and COX-2 levels were not significantly altered between benign and malignant thyroid nodules (IGF-II) or nodular (FTC, TTN, CTN) and normal thyroid tissues (COX-2). In contrast, eight- to tenfold upregulation of ets-1 was observed in PTC and three- to fourfold upregulation of ets-1 was observed in FTC (and GD) compared with benign thyroid nodules and normal thyroid tissues. In addition, thyroglobulin mRNA expression was markedly downregulated (50- to 100-fold) in FTC, PTC and GD samples compared with benign nodular and normal thyroid tissues. Hence an ets-1/Tg ratio >20 distinguished differentiated thyroid cancer from benign nodular or normal thyroid tissue. We then studied ets1- and Tg mRNA expression levels in fine needle aspiration cytology (FNAC) samples. However, in a consecutive series of 40 FNAC samples only equivocal results were obtained on 38 benign and two malignant (FTC) thyroid tumour samples.

CONCLUSIONS

Upregulation of ets-1 and downregulation of Tg mRNA expression occur in differentiated thyroid cancer and may facilitate pre-operative identification of thyroid malignancy depending on further evaluation of these potentially promising markers in a larger series of benign and malignant thyroid tumours and their FNAC samples.