Attitude of Older People Toward Living Donation

BACKGROUND

Living donation is a potential source of organs that could help to reduce the organ transplant deficit. Given that we have a worldwide aging population, it is important to assess the opinion of older people toward this type of donation.

OBJECTIVES

To analyze the attitude of people aged > 65 years toward living kidney donation (LKD) and living liver donation (LLD) and to investigate the variables affecting their attitudes.

METHODS

A multicentric study was carried out using a representative sample of people > 65 years stratified by sex and geographic location in southeastern Spain (n = 420). The measurement instrument was a validated questionnaire about LKD and LLD. Statistics were analyzed using SPSS version 21.0 (IBM Corp, Armonk, NY, United States) software. Descriptive analysis was carried out using Student t test, χ² test, and a multivariate analysis.

RESULTS

The questionnaire completion rate was 84% (n = 351) with 88% (n = 310) in favor of LKD, and 89% (n = 311) in favor of LLD. Favorable attitude decreased to 3% when the donation under consideration was unrelated. Attitudes toward LKD and LLD were associated with having received information from the television (P = .016 and P = .045) and from friends (P = .017 and P = .03); accepting an autopsy after death (P = .001 and P = .002); and not being worried about scars (P = .015 and P = .044). In the multivariate analysis, the following variables continued to be significant: having received information from the television (odds ratio [OR], 2) and from friends (OR, 10.3); and the acceptance of an autopsy (OR, 2).

CONCLUSIONS

Older people are in favor of both LKD and LLD, assuming it is a related donation. In addition, the information the elderly population receives regarding organ donation and transplantation affects their attitudes.

Elective and Onco-fertility preservation: factors related to IVF outcomes

STUDY QUESTION

Is the indication for fertility preservation (FP) related to success in IVF cycles after elective-FP (EFP) for age-related fertility decline and FP before cancer treatment (Onco-FP)?

SUMMARY ANSWER

Although success rates were lower in cancer patients, there was no statistically significant association between malignant disease and reproductive outcome after correction for age and controlled-ovarian stimulation (COS) regime.

WHAT IS KNOWN ALREADY

FP is increasingly applied in assisted reproduction, but little is known about the outcome of IVF cycles with vitrified oocytes in FP patients.

STUDY DESIGN, SIZE, DURATION

Retrospective, observational multicenter study of vitrification cycles for FP and of the warming cycles of women who returned to attempt pregnancy from January 2007 to May 2018.

PARTICIPANTS/MATERIALS, SETTING, METHODS

In all, 6362 women (EFP = 5289 patients; 7044 cycles + Onco-FP = 1073 patients; 1172 cycles) had their oocytes vitrified for FP. A logistic regression analysis was performed to examine the impact of indication for FP corrected for age at vitrification. The protocol used for COS was also included as a possible confounder. The main outcome measures were oocyte survival and live birth. A detailed description of the baseline and clinical data is provided, with comparisons between EFP and Onco-FP. The cumulative live birth rate (CLBR) per utilized oocyte according to age at vitrification was analyzed in those patients returning to use their oocytes.

MAIN RESULTS AND ROLE OF CHANCE

Age at vitrification was significantly older in EFP patients (37.2 ± 4.9 vs. 32.3 ± 3.5 year; P < 0.0001). Fewer oocytes were retrieved and vitrified per cycle in EFP (9.6 ± 8.4 vs. 11.4 ± 3.5 and 7.3 ± 11.3 vs. 8.7 ± 2.1, respectively; P < 0.05), but numbers became comparable when analyzed per patient (12.8 ± 7.4 vs. 12.5 ± 3.2 and 9.8 ± 6.4 vs. 9.5 ± 2.6). Storage time was shorter in EFP (2.1 ± 1.6 vs. 4.1 ± 0.9 years; P < 0.0001). In all, 641 (12.1%) EFP and 80 (7.4%) Onco-FP patients returned to attempt pregnancy (P < 0.05). Overall oocyte survival was comparable (83.9% vs. 81.8%; NS), but lower for onco-FP patients among younger (≤35 year) subjects (81.2% vs. 91.4%; P > 0.05). Fewer EFP cycles finished in embryo transfer (50.2% vs. 72.5%) (P < 0.05). The implantation rate was 42.6% and 32.5% in EFP versus Onco-FP (P < 0.05). Ongoing pregnancy (57.7% vs. 35.7%) and live birth rates (68.8% vs. 41.1%) were higher in EFP patients aged ≤35 than the Onco-FP matching age patients (P < 0.05). The reason for FP per se had no effect on oocyte survival (OR = 1.484 [95%CI = 0.876-2.252]; P = 0.202) or the CLBR (OR = 1.275 [95%CI = 0.711-2.284]; P = 0.414). Conversely, age (<36 vs. ≥36 y) impacted oocyte survival (adj.OR = 1.922 [95%CI = 1.274-2.900]; P = 0.025) and the CLBR (adj.OR= 3.106 [95%CI = 2.039-4.733]; P < 0.0001). The Kaplan-Meier analysis showed a significantly higher cumulative probability of live birth in patients <36 versus >36 in EFP (P < 0.0001), with improved outcomes when more oocytes were available for IVF.

LIMITATIONS, REASONS FOR CAUTION

Statistical power to compare IVF outcomes is limited by the few women who came to use their oocytes in the Onco-FP group. The patients' ages and the COS protocols used were significantly different between the EFP and ONCO-PP groups.

WIDER IMPLICATIONS OF THE FINDINGS

Although the implantation rate was significantly lower in the Onco-FP patients the impact of cancer disease per se was not proven'. EFP patients should be counseled according to their age and number of available oocytes.

STUDY FUNDING/COMPETING INTEREST(S)

No external funding was used for this study. The authors have no conflicts of interest.

TRIAL REGISTRATION NUMBER

N/A.

Evaluation of the registration of temporal series of contrast-enhanced perfusion magnetic resonance 3D images of the liver

The registration of 2D and 3D images is one of the key tasks in medical image processing and analysis. Accurate registration is a crucial preprocessing step for many tasks; consequently, the evaluation of its accuracy becomes necessary. Unfortunately, this is a difficult task, especially when no golden pattern (true result) is available and when the signal values may have changed between successive images to be registered. This is the case this paper deals with: we have a series of 3D images, magnetic resonance images (MRI) of the liver and adjacent areas that have to be registered. They have been taken while a contrast is diffused through the liver tissue, so intensity of each observed point changes for two reasons: contrast diffusion/perfusion and deformation of the liver (due to body movement and breathing). In this paper, we introduce a new method to automatically compare two or more registration algorithms applied to the same case of a perfusion magnetic resonance dynamic image so that the best of them can be chosen when no ground truth is available. This is done by modeling the function that gives the intensity at a given point as a functional datum, and using statistical techniques to assess its change in comparison with other functions. An example of the application is shown by comparing two parametrizations of a B-spline based registration algorithm. The main result of the proposed method is a suggestive evidence to guide the physician in the process of selecting a registration algorithm, that recommends the algorithm of minimal complexity but still suitable for the case to be analyzed.

Measurement of the neutron F2 structure function via spectator tagging with CLAS

We report on the first measurement of the F(2) structure function of the neutron from the semi-inclusive scattering of electrons from deuterium, with low-momentum protons detected in the backward hemisphere. Restricting the momentum of the spectator protons to ≲100 MeV/c and their angles to ≳100° relative to the momentum transfer allows an interpretation of the process in terms of scattering from nearly on-shell neutrons. The F(2)(n) data collected cover the nucleon-resonance and deep-inelastic regions over a wide range of Bjorken x for 0.65<Q(2)<4.52 GeV(2), with uncertainties from nuclear corrections estimated to be less than a few percent. These measurements provide the first determination of the neutron to proton structure function ratio F(2)(n)/F(2)(p) at 0.2≲x≲0.8 with little uncertainty due to nuclear effects.

Results of liver transplantation from donors over 75 years: case control study

INTRODUCTION

The use of elderly donors can increase the pool of organs available for transplant. The aim of this study was to analyze the outcomes of grafts from donors older than 75 years.

PATIENTS AND METHODS

We selected 29 patients transplanted from January 2003 to January 2010 with livers from donors older than 75 years for comparison with a control group (58 patients), selected among patients transplanted immediately before or after each study case. Data analyzed using SPSS 15.0 were considered statistically significant at P < .05.

RESULTS

Statistically significant differences were evident in the mean age of donors (78.3 ± 2.9 vs 50.4 ± 17.8 years, P < .001), levels of aspartate aminotransferase alanine aminotransferase (30.8 ± 18.13/24.9 ± 14.4 vs 53.81 ± 68.4/39.37 ± 39.94 U/L, P < .05), and waiting list time of (122.4 ± 94.3 vs 169.2 ± 135.5 days, P = .034) of elderly donor versus control graft cohorts. The median follow-up was 32 months (range: 4-88.0) No differences were observed at 1 and 3 years after transplantation: graft survival was 78% and 61% in the older donor group and 83% and 71% in the younger donor group, respectively.

CONCLUSION

The use of expanded donors from elderly subjects can increase the donor pool with good results.

Improving the waiting list by using 75-year-old donors for recipients with hepatocellular carcinoma

The best treatment for hepatocellular carcinoma (HCC) associated with liver cirrhosis is liver transplantation and the best results are obtained when the tumors fulfill the Milan criteria. However, although the number of transplants is increasing, the organ deficit is growing, which lengthens time on the waiting list, increasing the risk of tumor progression of and exclusion from the list. The use of elderly donors is a valid option for patients on the transplant waiting list with HCC, reducing time on the waiting list. We report our experience with patients transplanted for HCC associated with hepatic cirrhosis using livers from donors >75 years of age. Our preliminary results supported the use of elderly suboptimal donors making it possible to give priority to these patients. All patients in the series achieved good graft function after a follow-up of 2 years with a 100% disease-free survival rate. More extensive long-term studies are needed to confirm these findings.

Semi-automated evaluation tool for retinal vasculopathy

The ocular fundus is the only area of human body where vascular system is visible using relatively simple instrumentation. Furthermore, there is medical suggestive evidence of a direct relationship between certain measures of vascular characteristics in the ocular fundus (arteriolar and venular calibers and focal arteriolar narrowing) and cardiovascular diseases. In order to establish such relationship on sound statistical basis a method must be provided to measure the needed values in an easy, yet precise and repeatable way. This paper presents a system to assist physicians in signaling and storing the data associated to signs of vascular deterioration and vascular calibers in non-mydriatic ocular fundus images. The system is built around a graphical user interface that, even not fully automatic, guides the practitioner to mark certain anatomic visible features in an easy and precise way. The data are exported in common database formats for further processing and a statistical summary is also presented.

Vitrification: an effective new approach to oocyte banking and preserving fertility in cancer patients

INTRODUCTION

Oocyte cryopreservation is a useful tool for preserving the fertility of cancer patients at risk of losing ovarian function due to undergoing potentially sterilising therapies. Results obtained with different cryopreservation protocols have been disappointing, particularly those obtained with slow cooling procedures. The efficacy of vitrification as an application in clinical practice has recently been demonstrated. The aim of this study is to report results obtained with the Cryotop method of oocyte vitrification in a population of healthy women and to point out its potential usefulness for fertility preservation in oncological patients.

MATERIALS AND METHODS

The study population consisting of non-oncological patients included 47 oocyte donors and 57 recipients undergoing an oocyte donation cycle of assisted reproductive technology (ART). A total of 693 mature metaphase II oocytes were collected following ovarian stimulation using long protocol down-regulation plus gonadotropin administration. Vitrification was carried out by means of the Cryotop method. Oocytes were donated to a compatible recipient after endometrial preparation.

RESULTS

Of the 693 oocytes, 666 (96.1%) survived. A total of 487 (73.1%) were fertilised successfully. One hundred and seventeen embryos were transferred to 57 recipients. Pregnancy rate per transfer and implantation rates were 63.2% and 38.5% respectively. Twenty-eight healthy babies were later born.

CONCLUSIONS

Oocyte cryo-banking by means of the Cryotop vitrification method represents a viable option for healthy women, producing excellent survival rates and a clinical outcome similar to that obtained with fresh oocytes. This approach could potentially be used in cancer patients who want to safeguard their fertility. Cancer patients could potentially benefit from this approach by storing their oocytes before the onset of the oncological therapy.

The incidence of distal forearm fractures in Zaragoza (Spain)

We present the results of a retrospective study of the epidemiology of distal forearm fractures in patients over 15 years of age in Zaragoza (Spain) during 1998-1999. We analysed a total of 2506 fractures of the distal forearm. Fractures were classified according to age, sex, Frykman classification and mechanism of injury. Fractures were Frykman type III in 23.5% of cases, Frykman II in 17.9%, Frykman IV in 14.5% and Frykman I in 12.8%. The rest of fractures were distributed homogeneously between the remaining fracture types. The mechanisms of injury was low energy in 78.2% of cases and high in 21.8%. Analysis of the age distribution showed an increase in the incidence of this type of fracture over 50 years of age, with a peak between 60 and 69 years as a result of accidental falls. We found an increased incidence in males below 49 years of age, as a result of traffic accidents, and a predominance of females over 50 years of age due to osteoporosis and an increased number of falls.

Molecular diversity and multilocus organization of the parental lines used in the International Rice Molecular Breeding Program

One hundred and ninety three parental lines obtained from 26 countries for an international rice molecular breeding program were evaluated using 101 well-distributed simple sequence repeat (SSR) markers. An overall genetic diversity of 0.68 and an average of 6.3 alleles per locus were revealed, indicating a high level of genetic variation in these lines. Cluster analysis of the 193 accessions showed three major groups and nine subgroups. Group I corresponded to the classical indica subspecies, whereas groups II and III belong to the japonica subspecies. Indica and japonica differentiation accounted for only 6.5% of the total variation in the entire sample and 93.5% was due to within-subspecies diversity. Differentiation among eco-geographic regions accounted for 24% of the diversity within the subspecies. Larger amounts of the eco-geographical differentiation were resolved within japonica than within indica. The largest indica-japonica differentiation based on the single locus level was detected by markers on chromosomes 9 and 12, while the smallest differentiation was detected by markers on chromosomes 4 and 8. Furthermore, genetic differences at the single-locus and two-locus levels, as well as components due to allelic and gametic differentiation, were revealed between indica and japonica and among the main geographic regions. The multilocus analysis in genetic diversity showed a higher proportion of variation caused by predominant non-random associations of different loci within and among the classified subspecies and geographic subdivisions. The results suggest that selection for eco-geographical adaptation on multilocus associations was largely responsible for the maintenance of the extensive variation in the primary gene pool of rice.

[Non-detected dementia and use of the health services: implications for primary care]

OBJECTIVES

To calculate the proportion of cases of dementia detected in people over 70 living in their homes and to describe the use made by people with dementia of the health and social services.

MATERIAL AND METHODS

Population survey of the survivors of the cohort "Growing old in Leganés", started in 1993. In the third monitoring (1999-2000), the clinical diagnosis of dementia on the basis of a neurological examination and an extensive neuro-psychological battery was included. Their use of health and social services and prior diagnoses were also asked.

RESULTS

In the sample of survivors (n=527), there was 12.1% prevalence of dementia. Only 30% of the demented had previously been diagnosed by the health services. The proportion of undetected dementia was significantly associated with its seriousness (light 95%, moderate 69%, severe 36%). Compared with older persons who were not demented, the demented used more often hospital services, medical and nursing consultations at home and consultations through third parties; and less often, preventive and rehabilitation services. This trend was accentuated in patients with grave dementia. The use of community social services was very low (below 8% in the most serious cases).

CONCLUSIONS

The detection of dementia in the elderly is very low and efforts to detect it in primary care need to be stepped up. Specific social-health resources for this population also need to be increased and the attendance guide-lines for primary care teams, and for health professionals in general, need to be changed.

Are the dominant and recessive plant disease resistance genes similar? A case study of rice R genes and Xanthomonas oryzae pv. oryzae races

The resistance of rice to its bacterial blight pathogen Xanthomonas oryzae pv. oryzae (Xoo) has both qualitative and quantitative components that were investigated using three near-isogenic line sets for four resistance (R) genes (Xa4, xa5, xa13, and Xa21) and 12 Xoo races. Our results indicate that these two resistance components of rice plants were associated with the properties of the R genes. The qualitative component of the R genes was reflected by their large effects against corresponding avirulent Xoo races. The quantitative component of the R genes was their residual effects against corresponding virulent races and their epistatic effects, which together could lead to high-level resistance in a race-specific manner. Our results revealed important differences between the different types of R genes. Two R genes, Xa4 and Xa21, showed complete dominance against the avirulent Xoo races and had large residual effects against virulent ones. They acted independently and cumulatively, suggesting they are involved in different pathways of the rice defensive system. The third R gene, xa5, showed partial dominance or additivity to the avirulent Xoo races and had relatively small but significant residual effects against the virulent races. In contrast, xa13 was completely recessive, had no residual effects against the virulent races, and showed more pronounced race specificity. There was a strong interaction leading to increased resistance between xa13 and xa5 and between either of them and Xa4 or Xa21, suggesting their regulatory roles in the rice defensive pathway(s). Our results indicated that high-level and durable resistance to Xoo should be more efficiently achieved by pyramiding different types of R genes.

Hyperhomocyst(e)inemia is a risk factor of secondary vascular events in stroke patients

OBJECTIVE

Moderate hyperhomocyst(e)inemia is an independent risk factor for stroke, but it is unclear whether it also would be a risk factor for secondary vascular events after stroke.

METHODS

Longitudinal study of 137 consecutive ischemic stroke patients (age 45-91 years) who were prospectively studied with a standard clinical protocol. Vascular events (stroke recurrence, ischemic heart disease, deep venous thrombosis or peripheral arterial disease) were identified during 2 years of follow-up. Serum homocyst(e)ine was determined 3 months after the stroke. The cumulative proportion of patients with homocyst(e)ine above or below the 75th percentile who survived free of vascular events was determined by Kaplan-Meier analysis. Cox models were used to estimate the relative risk of vascular events after controlling for other confounding factors.

RESULTS

Serum homocyst(e)ine was significantly higher in patients with vascular events (26.2 versus 19.4 micromol/l; p = 0.016). The cumulative proportion of patients with vascular events was 46.5% in the group with homocyst(e)ine over the 75th percentile (>30 micromol/l) and 20.2% in the other group (log-rank test 7.5; p = 0.0062). After adjustment for age, sex, high blood pressure, diabetes, heart disease, previous cerebrovascular disease, smoking and serum cholesterol, the relative risk of vascular event for patients above compared with those below the 75th percentile of serum homocyst(e)ine was 2.8 (CI 95% 1.3-6; p = 0.01).

CONCLUSION

Hyperhomocyst(e)inemia is a significant risk factor for vascular events after ischemic stroke. This finding is independent of other risk factors such as hypertension, and may have therapeutic relevance in the secondary prevention of vascular diseases in stroke patients.

Dynamics of the 16O(e, e'p) reaction at high missing energies

We measured the cross section and response functions for the quasielastic 16O(e,e'p) reaction for missing energies 25< or =E(m)< or =120 MeV at missing momenta P(m)< or =340 MeV/c. For 25<E(m)<50 MeV and P(m) approximately 60 MeV/c, the reaction is dominated by a single 1s(1/2) proton knockout. At larger P(m), the single-particle aspects are increasingly masked by more complicated processes. Calculations which include pion exchange currents, isobar currents, and short-range correlations account for the shape and the transversity, but for only half of the magnitude of the measured cross section.

Atraumatic spontaneous posterior subluxation of the sternoclavicular joint

We report a case of atraumatic spontaneous posterior subluxation of the sternoclavicular joint in a 19-year-old woman without any known underlying pathology. There was no history of injury. The patient was treated operatively using the gracilis tendon to reinforce the anterior sternoclavicular ligament. One year later the patient is asymptomatic and has returned to her usual life.

Macular edema computer-aided evaluation in ocular vein occlusions

This paper is concerned with the use of digital fundus imaging to detect, quantify, and follow up macular angiographic leakage due to retinal vein occlusions. Images were matched automatically. We detected those pixels with a high increment in gray level within the closest area to the foveal center. Binary images displaying leakage were obtained. The procedure was checked against two observers' agreement. Twenty-one angiographic studies were collected. Two images of each sequence were selected for digitalization. Numerical descriptors of the leakage were proposed and quantification plots were designed for each pair of images. Interobserver concordance ranged between 82 and 98% when manually detected leakage was compared with computer segmented areas. The detection and quantification of leakage areas may serve as a guide for severity evaluation and treatment planning. Moreover, they permit a precise follow-up of macular edema.

Screening for overlapping bacterial artificial chromosome clones by PCR analysis with an arbitrary primer

In this article, we used PCR analysis with arbitrary primers (AP-PCR) to screen for overlapping bacterial artificial chromosome (BAC) clones and assembly of contigs. A rice BAC library with three genome equivalents was used to prepare pooled BAC DNA. Twenty-two arbitrary primers were used to survey the pooled BAC DNAs and individual BAC DNAs. Each primer identified 1-10 loci, and the average was 4.4 loci. There were 1-5 overlapping clones in each locus, and the average was 2.5 clones. A total of 245 BAC clones were identified as overlapping by AP-PCR and the identities were confirmed by DNA-DNA hybridization. The 245 BAC clones were then assembled into 80 contigs and 17 single-clone loci. The results indicated that PCR analysis with arbitrary primers is a powerful tool in screening for overlapping BAC clones with high accuracy and efficiency. The use of AP-PCR analysis should speed up the construction of physical maps of the plant and animal genomes, as well as the rice genome.

Gallbladder dyskinesia in acalculous biliary colic

AIMS

To test the hypotheses that: 1) postprandial gallbladder emptying might be abnormal in patients with acalculous biliary colic; and 2) that hymecromone, a drug that increases bile flow and relaxes biliary muscle might improve symptoms.

METHODS

Twenty-four women were studied. Twelve patients presented recurrent biliary type of pain in the absence of gallstones, and persistence of contrast in the gallbladder, 24 hours after an oral cholecystogram, suggesting cholesterolosis. Twelve healthy volunteers used as controls had no symptoms and the gallbladder was not visible the day after an oral cholecystogram. Gallbladder emptying induced by an oral meal was studied with ultrasound in both groups before and after the administration of hymecromone.

RESULTS

Gallbladder volumes were similar in both groups (23 +/- 10 ml vs. 31 +/- 11 ml; NS). Gallbladder emptying in the control group was simple exponential (R2 = 0.948 +/- 0.059) with a rate of 32 +/- 16 minutes. Gallbladder emptying was bimodal in patients. Gallbladder volume increased to 120% in the first 10 minutes, to empty exponentially thereafter (R2 = 0.964 +/- 0.040. Rate: 29 +/- 22 minutes). This resulted in a marked reduction in gallbladder volume emptied at 40 minutes when compared to controls (30% +/- 27% vs. 54% +/- 14%; p = 0.012). Pretreatment of controls with hymecromone induced an emptying pattern similar to that of patients. In patients, emptying after hymecromone did not change but symptoms were improved.

CONCLUSIONS

An abnormal emptying pattern of the gallbladder was identified in patients with acalculous biliary colic, and hymecromone was partly effective to reduce pain, despite a minor effect on gallbladder emptying pattern.

Species-specific identification of Candida krusei by hybridization with the CkF1,2 DNA probe

The species specificity of the Candida krusei DNA fingerprinting probe CkF1,2 has been investigated. A total of 149 pathogenic and nonpathogenic fungal and bacterial DNAs were screened with CkF1,2. The probe was cold labeled with peroxidase, and its specificity was assessed by using Southern blot, dot blot, and colony blot hybridization. Its sensitivity was determined by dot blot hybridization. The CkF1,2 probe proved to be species specific. It hybridized with DNA for the 112 C. krusei strains studied, whereas it failed to hybridize under low-stringency conditions to 37 DNAs from 27 different yeast species, including Candida albicans, Candida glabrata, Candida norvegensis, Candida inconspicua, Candida tropicalis, Candida valida, Candida zeylanoides, and Yarrowia lipolytica, as well as DNAs from the filamentous fungi and bacteria tested. However, CkF1,2 hybridized strongly with DNA of the yeast species Issatchenkia orientalis, the putative ascogenous perfect state of C. krusei. Amounts as small as 60 to 120 ng of C. krusei target DNA were detected by dot blot hybridization with CkF1,2. It permitted the direct screening of colony blots for early identification. The CkF1,2 probe has potential value as a diagnostic reagent for identifying C. krusei.

Immunohistochemical localization of transforming growth factor-alpha in choroid plexus of the rat and chicken

Transforming growth factor-alpha (TGF-alpha) is a polypeptide which binds to epidermal growth factor-receptor (EGF-R) to carry out its function. We have observed strong TGF-alpha immunoreactivity in the developing and adult choroid plexus of the rat and chicken and glial cells of adult rats, by using a well characterized monoclonal antibody and the peroxidase method. Preabsortion of the antibody with the peptide gave negative staining. Since previous studies have shown that EGF-R is localized in several brain regions, but not in the choroid plexus, during development and adulthood, it is suggested that TGF-alpha, synthesized in the choroid plexus and transferred to the cerebrospinal fluid, has a role in brain development. TGF-alpha immunoreactivity found in glial cells, but not in neurons of adult rats, suggests that TGF-alpha in adulthood is also synthetized in the glial cell compartment.

Immunohistochemical localization of transforming growth factor-alpha and epidermal growth factor-receptor in the mesonephros and metanephros of the chicken

Transforming growth factor-alpha (TGF-alpha) is a polypeptide related to epidermal growth factor (EGF). Both bind to EGF-receptor (EGF-R) to carry out their function in a variety of tissues and cell lines. Several studies have shown their presence in mammalian kidney, however, nothing has to date been stated concerning their existence in avian kidney. Expression of TGF-alpha and EGF-R is reported here for the first time during the development of the chicken kidney. Using immunohistochemical techniques, we identified a TGF-alpha (but not EGF) in mesonephric distal tubule cells from day 8 to day 20 of embryonic development and in metanephric distal tubule cells from day 14 of embryonic development to the adult. The histochemical characteristics of these cells and their histological localization suggest that they may be the "principal cells" of the distal tubules. Similarly, EGF-R was found in mesonephric proximal tubule cells from day 7 to day 18 of embryonic development and in metanephric proximal tubule cells from day 13 of embryonic development up to adult stages. The coexistence of both TGF-alpha and EGF-R from the onset of development of mesonephros and metanephros supports their possible role in mechanisms of proliferation and differentiation of the cells of these organs.

Hough-transform system with optical anamorphic preprocessing and digital postprocessing

A modification of the optical Hough transformer [Appl. Opt. 25, 2734-2738 (1986)] is proposed. An input image is optically preprocessed to obtain an anamorphic magnified image. The anamorphic magnification leads to improved accuracy of the output plane parameter theta determination by means of a simple version of a Hough transformer. Then, the output signal is digitally postprocessed to obtain subpixel resolution in the rho parameter dimension. A description of the method and the experimental results is presented.

Somatostatin is altered in developing retina from ethanol-exposed rats

Optic nerve hypoplasia is seen in 50% of patients diagnosed with fetal alcohol syndrome and is due to a defect in the development of retinal ganglion cells. Somatostatin may influence the development of retinal ganglion cells, so we studied the effect of in vivo ethanol exposure on somatostatin expression in the developing retina. Somatostatin concentration is increased in retina from ethanol-exposed fetuses and pups and this increase in peptide is associated with excessive neurite formation and improper migration of the somatostatin-containing neurons at early postnatal ages. These disturbances may account for the eventual failure in retinal ganglion cell development that results in optic nerve hypoplasia.

Transforming growth factor-alpha expression in rat experimental hepatocarcinogenesis

Growth factors in general and transforming growth factor-alpha in particular have been related to cell proliferation and cell differentiation. This study was designed to clarify the distribution pattern of TGF-alpha in chemically-induced hepatocarcinogenesis. Sprague-Dawley rats were subjected to different non-intensive or intensive carcinogenic treatments using diethylnitrosamine (DEN) as carcinogen and ethinyl estradiol (EE) as promoter. The livers were fixed in 2% paraformaldehyde, dehydrated in a series of ethanol solutions, embedded in paraffin and sectioned. In the preneoplastic lesions no TGF-alpha immunoreactive cells were identified, but in some hepatic tumours cell immunostained with TGF-alpha antibody were observed. These results suggest that the cells capable of expressing TGF-alpha constitutively may be involved in neoplastic development in vivo.