Cell membrane and mitotic markers show that the neonatal rat gubernaculum grows in a similar way to an embryonic limb bud

Aim/Background

How the gubernaculum guides the testis into the scrotum remains controversial, with various proposals from passive inversion to active growth. We aimed to determine if the gubernaculum contains an area of active proliferation, such as a “progress zone” in a growing embryonic limb bud, using a fluorescent cell membrane marker, 1,1′-didodecyl-3,3,3′,3′-tetramethylindocarbocyanine perchlorate [DiIC₁₂(3)], to trace cell migration, and 5-bromodeoxyuridine (BUDR) (a thymidine analogue) as a mitotic marker.

Methods

Gubernacula were collected from neonatal male rats (n = 42, day 1-2, Sprague-Dawley) and cultured with calcitonin gene-related peptide (CGRP; 714 nmol/L). 1,1′-didodecyl-3,3,3′,3′-tetramethylindocarbocyanine perchlorate-coated glass beads (diameter, 150-212 μm) were placed next to the bulb for the first 3 hours. Gubernacula were cultured for 3, 18, and 24 hours, then frozen sections cut and examined by confocal microscopy (wavelength, 549 nm). In a second experiment, pups not exposed to exogenous CGRP (n = 53, day 0, Sprague-Dawley) were injected intraperitoneally with BUDR (50 mg/kg of body weight); gubernacula were collected at 2, 48, 72, and 96 hours postinjection (PI), sectioned, and stained using immunohistochemistry to count the number of BUDR-positive cells per 100 cells (labeling index) in the bulb, cremaster, cord, and epididymis.

Results

After 24 hours' culture with CGRP, the bulb showed an oval region (diameter, 300 μm) of high fluorescence, and the cremaster region showed elongated cells migrating out of the bulb. When cultured without CGRP, the same oval region contained no fluorescence. In vivo BUDR labeling index increased in all areas until 48 hours postinjection and then decreased most rapidly in the bulb (P < .05), in the presence of endogenous CGRP from the genitofemoral nerve.

Conclusions

The rat gubernaculum contains a putative progress zone, such as in a growing limb bud, in the presence of CGRP. Cells migrate out of this zone to form cremaster muscle. We hypothesize that proliferation in the bulb elongates the gubernaculum, whereas proliferation of cremaster cells would increase gubernacular diameter. This brings to “life” the gubernaculum as an actively growing organ in contrast to the inert ligament connecting the testis to the scrotum portrayed in most anatomy textbooks.     

Follow-up After Curative Resection of Colorectal Cancer

Of the 13.7 million cancer survivors living in the United States as of January 2012, 1.2 million, or 9 %, were colorectal cancer (CRC) survivors. Determining an optimal surveillance for CRC survivors is necessary because of the significant burden follow-up poses to patients, physicians, and the health care system. Currently, there is no consensus regarding optimal follow-up in CRC patients. Current literature and published guidelines related to CRC follow-up were reviewed to examine the evidence for the surveillance strategies and specific tools demonstrated to improve outcome after curative CRC resection. An intensive surveillance strategy results in increased identification of recurrences amenable to curative resection but does not result in reduced overall or CRC-specific mortality. Patients most likely to benefit from surveillance include younger patients, those with earlier tumors, locoregional recurrences, longer time to recurrence, lower carcinoembryonic antigen (CEA) levels before reoperation, and those with isolated recurrence. Complete resection of recurrence is the only factor consistently associated with improved survival. CEA, colonoscopy, and liver-focused imaging surveillance appear to have the greatest impact on mortality after curative CRC resection. A CRC surveillance strategy is recommended that includes tumor risk stratification, that provides a focus on identifying recurrences amenable to complete resection, and that utilizes those modalities demonstrated to be most effective at improving outcome after CRC resection.     

Alcohol use disorders, nicotine dependence, and co-occurring mood and anxiety disorders in the United States and South Korea-a cross-national comparison

Background: The strong comorbidity between substance use disorders (SUDs) and mood and anxiety disorders has been well documented. In view of lack of research findings addressing the co‐occurrence of SUDs and mood and anxiety disorders, this study examined the pattern of comorbidity of alcohol use disorders (AUDs) and nicotine dependence (ND) between 2 culturally diverse countries, the United States and South Korea. Methods: Using the nationally representative samples of the U.S. and Korean general populations, we directly compared rates and comorbidity patterns of AUDs, ND, and mood and anxiety disorders between the 2 countries. We further examined the rates and the comorbidity pattern among individuals with AUDs who sought treatment in the last 12 months. Twelve‐month prevalence rates were derived to estimate country differentials, and odds ratios (ORs) and 95% confidence intervals were estimated to measure the strength of comorbid associations while adjusting for all sociodemographic characteristics in multivariate logistic models specific to each country. Results: The 12‐month prevalence rates of AUDs, ND, and any mood disorder and any anxiety disorder were 9.7, 14.4, 9.5, and 11.9% among Americans, whereas the corresponding rates were 7.1, 6.6, 2.0, and 5.2% among Koreans. These rates were significantly greater (except for any AUD) among Americans than among their Korean counterparts. With respect to comorbidity, both countries showed comparable patterns that the prevalence rates of mood and anxiety disorders were consistently the highest among persons with alcohol dependence (AD). Also, a disparate pattern was observed in Korea that the prevalence rates of mood and anxiety disorders were generally lower among individuals with ND than among those with alcohol abuse and AD. Furthermore, despite significantly greater prevalence of AD in Korea (5.1%) than in the United States (4.4%), alcohol‐dependent Americans were 4 times (OR = 3.93) more likely to seek treatment compared to their Korean counterparts. Conclusions: Our results indicated that the prevalence of AD in Korea was substantially greater than that in both Western and other Asian countries, suggesting a maladaptive pattern of alcohol use in Korea, which is different from the general use pattern of other East Asian countries. The low rate of treatment utilization among Koreans might be attributable to perceived social stigma toward SUDs or mental health problems despite the fact that the Korean government offers national health insurance.     

Estrogen receptor GPR30 reduces oxidative stress and proteinuria in the salt-sensitive female mRen2.Lewis rat

The current study assessed whether activation of the novel estrogen receptor GPR30 ameliorates salt-dependent renal damage in intact mRen2.Lewis (mRen2) females. Hemizygous mRen2 rats were maintained on either a normal salt (0.5% Na) or high-salt (HS; 4.0% Na) diet for 10 weeks (5 to 15 weeks of age), and HS animals were treated with the GPR30 agonist G-1 or vehicle for 2 weeks. Systolic blood pressure markedly increased with HS diet (149±3 to 219±5 mm Hg; P<0.01), but G-1 did not influence pressure (P=0.42). G-1 and estradiol induced relaxation of preconstricted mesenteric vessels from normal salt mRen2 rats, but both responses were attenuated in the HS group. Despite the lack of an effect on blood pressure, G-1 decreased renal hypertrophy, proteinuria, urinary 8-isoprostane excretion, and tubular 4-hydroxynonenal staining. HS diet significantly increased GPR30 mRNA (1.01±0.04 versus 1.59±0.13; P<0.01) and protein (0.60±0.31 versus 3.99±0.75; P<0.01) in the renal cortex. GPR30 was highly expressed in the brush border of proximal tubules and colocalized with megalin. Finally, megalin expression was reduced by HS diet and restored with G-1. We conclude that GPR30-mediated beneficial effects in salt-sensitive mRen2 females occurred independent of changes in systolic blood pressure. The failure of G-1 to influence pressure may reflect a salt-induced impairment in GPR30-mediated vasorelaxation. The renoprotective actions of GPR30 may involve attenuation of tubular oxidative stress and activation of megalin-mediated protein reabsorption.     

Balancing high accrual and ethical recruitment in paediatric oncology: a qualitative study of the 'look and feel' of clinical trial discussions

Background  

High accrual to clinical trials enables new treatment strategies to be tested rapidly, accurately and with generalisability. Ethical standards also must be high so that participation is voluntary and informed. However, this can be difficult to achieve in trials with complex designs and in those which are closely embedded in clinical practice. Optimal recruitment requires a balance of both ethical and accrual considerations. In the context of a trial of stratified treatments for children with acute lymphoblastic leukaemia (UKALL2003) we examined how recruitment looked to an observer and how it felt to the parents, to identify how doctors' communication could promote or inhibit optimal recruitment.     

Preventive care in prostate cancer patients: following diagnosis and for five-year survivors

Introduction  

Prostate cancer is the most common male cancer. Survival rates are high, making preventive care maintenance important. Factors associated with prostate-cancer cases’ preventive care in the short-term (Year 1) and long-term (Year 5), and how survivors’ care compares to non-cancer controls, require study.     

Multiple mechanisms of resistance in a series of human testicular teratoma cell lines selected for increasing resistance to etoposide

Mechanisms of resistance to VP-16 were monitored in a series of sublines of the human testicular teratoma cell line (SuSa) derived following exposure either to fractionated X-irradiation (DXR-10) or to VP-16 using pulsed 24-hr exposures (VP 10) or continuous exposure conditions (VPC2, VPC3 and VPC4). Orders of resistance expressed (ranging from 3- to 33-fold based on ICS0 values derived from colony forming assays) were comparable with those likely to be encountered clinically, All of these resistant sublines showed some cross -resistance to VCR, and the 3 drug-selected sublines tested also proved cross-resistant to ADR. Resistance was not associated with modified ³H-VP-16 accumulation. However, decreased VP-16-induced SSBs were detectable in all the resistant sublines and a strong positive correlation was noted between the extent of SSB formation and VP-16 resistance by linear regression analysis. Topo IIα protein content, as judged by Western blotting, was significantly decreased only in the sublines derived by continuous exposure to VP-16, but this was not progressive with increasing levels of resistance expressed. RNase protection assays also showed no significant differences in Topo IIα expression in the low-level resistant DXR-10 and VP 10 sublines, contrasting with the 2-fold decreases identified in the VPC2, VPC3 and VPC4 sublines. Significantly, however, mRNA levels of two alternately spliced Topo IIβ mRNAs were markedly decreased (2- to 9-fold) in all the drug-selected resistant sublincs. No mutations in consensus ATP-binding sequences or in the DNA-binding region of Topo Ma were detected by single strand conformations I polymorphism analysis. Significant Pgp over express ion was only identified in the most highly resistant sublines VPC3 and VPC4, which both showed 4-fold cross-resistance to VCR. Decreased ³H-VCR accumulation and partial reversal of resistance by VPM (6.6 μM) addition was also identified, consistent with a functional Pgp being overexpressed in these sublines. Modifications of Topo II expression therefore appear to precede Pgp overexpression in this series of sequentially derived VP-16 resistant sublines and to represent the predominate mechanism underlying low level (< 10-fold) resistance. © 1994 Wiley-Liss, Inc.     

Unlocking the numerator-denominator bias. I: Adjustments ratios by ethnicity for 1991-94 mortality data. The New Zealand Census-Mortality Study

AIM: To determine the extent of the under-reporting of M?ori and Pacific mortality among 0-74 year olds for the period 1991-94. METHODS: A subset (n=22,578) of highly probable linked 1991 census and 1991-94 mortality records were selected from the 31,635 census-mortality links in the New Zealand Census-Mortality Study. The numbers of decedents assigned as M?ori, Pacific, and non-M?ori non-Pacific were compared between mortality and census data. RESULTS: Compared to the death registration form, 29% more 0-74 year old decedents during 1991-94 had self-identified as sole-M?ori on the 1991 census (46% for prioritised-M?ori). This numerator-denominator bias was greater among the young and those living in central and southern New Zealand. Among 0-14, 15-24, 25-44, 45-64, and 65-74 year old decedents, respectively, 91%, 50%, 41%, 26% and 15% more decedents had self-identified as sole-M?ori on the 1991 census. For Northern, Midland, Central and Southern regional health authority areas, respectively, 14%, 17%, 81% and 102% more decedents had self-identified as sole-M?ori. Among Pacific decedents 68% more 0-74 year old decedents had self-identified as sole-Pacific on the 1991 census (78% for prioritised-Pacific group). This bias for Pacific decedents did not notably vary by age and region. CONCLUSIONS: This study confirms substantial underestimation of M?ori and Pacific mortality rates for the period 1991-94, even using the recommended sole-ethnic group denominator. The results from this study should be used to adjust ethnic-specific mortality rates for the early 1990s. Population-based funding formulas that included region-specific M?ori mortality rates would have particularly disadvantaged central and southern regions.