Vascular stenting of a malignant arterial blowout as a bridge to effective systemic and regional therapy

Locally advanced cutaneous squamous cell carcinoma can erode into blood vessels, leading to vascular blowout, requiring emergent surgical intervention. We describe a first case of this disease complication which was effectively managed with endovascular stenting as a bridge to effective systemic and regional therapy. We discuss the efficacy of this staged approach which is novel and timely in a clinical environment of increasingly effective systemic therapies.

Giant Colonic Diverticulum: A Rare Type of Diverticular Disease

Giant colonic diverticulum (GCD) is a well-recognized but infrequently encountered disease in clinical practice. GCD is its own unique entity and differs from commonly seen diverticular disease in both size and management. Initial clinical presentation is typically associated with diverticulitis and symptoms such as abdominal pain, fever, nausea, vomiting, rectal bleeding, or even a palpable abdominal mass. Surgery is the recommended treatment option largely due to the risk of associated complications including colonic perforation. We describe the case of a 56-year-old female diagnosed with a sigmoid GCD that was successfully stabilized medically and definitively treated surgically.

Quality of Surgical Care Within the Criminal Justice Health Care System

Importance

Individuals who are incarcerated represent a vulnerable group due to concerns about their ability to provide voluntary and informed consent, and there are considerable legal protections regarding their participation in medical research. Little is known about the quality of surgical care received by this population.

Objective

To evaluate perioperative surgical care provided to patients who are incarcerated within the Texas Department of Criminal Justice (TDCJ) and compare their outcomes with that of the general nonincarcerated population.

Design, Setting, and Participants

This cohort study analyzed data from patients who were incarcerated within the TDCJ and underwent general or vascular surgery at the University of Texas Medical Branch (UTMB) from 2012 to 2021. Case-specific outcomes for a subset of these patients and for patients in the general academic medical center population were obtained from the American College of Surgeons National Quality Improvement Program (ACS-NSQIP) and compared. Additional quality metrics (mortality index, length of stay index, and excess hospital days) from the Vizient Clinical Data Base were analyzed for patients in the incarcerated and nonincarcerated groups who underwent surgery at UTMB in 2020 and 2021 to provide additional recent data. Patient-specific demographics, including age, sex, and comorbidities were not available for analysis within this data set.

Main Outcome and Measures

Perioperative outcomes (30-day morbidity, mortality, and readmission rates) were compared between the incarcerated and nonincarcerated groups using the Fisher exact test.

Results

The sample included data from 6675 patients who were incarcerated and underwent general or vascular surgery at UTMB from 2012 to 2021. The ACS-NSQIP included data (2012-2021) for 2304 patients who were incarcerated and 602 patients who were not and showed that outcomes were comparable between the TDCJ population and that of the general population treated at the academic medical center with regard to 30-day readmission (6.60% vs 5.65%) and mortality (0.91% vs 1.16%). However, 30-day morbidity was significantly higher in the TDCJ population (8.25% vs 5.48%, P = .01). The 2020 and 2021 data from the Vizient Clinical Data Base included 629 patients who were incarcerated and 2614 who were not and showed that the incarcerated and nonincarcerated populations did not differ with regard to 30-day readmission (12.52% vs 11.30%) or morbidity (1.91% vs 2.60%). Although the unadjusted mortality rate was significantly lower in the TDCJ population (1.27% vs 2.68%, P = .04), mortality indexes, which account for case mix index, were similar between the 2 populations (1.17 vs 1.12).

Conclusions and Relevance

Findings of this cohort study suggest that patients who are incarcerated have equivalent rates of mortality and readmission compared with a general academic medical center population. Future studies that focus on elucidating the potential factors associated with perioperative morbidity and exploring long-term surgical outcomes in the incarcerated population are warranted.

Laparoscopic and robotic pyeloplasty as minimally invasive alternatives to the open approach for the treatment of uretero-pelvic junction obstruction in infants: a multi-institutional comparison of outcomes and learning curves

BACKGROUND

Since the development of minimally invasive surgery (MIS), laparoscopic and robotic approaches have been widely adopted. However, little has been published detailing the learning curve of MIS, especially in infants.

OBJECTIVE

To quantify the learning curve of laparoscopic (LP) and robot-assisted laparoscopic pyeloplasty (RAL-P) for treatment of uretero-pelvic junction obstruction (UPJO) in infants evidenced by number of cases, operative time, success and complications.

PATIENTS AND METHODS

Between 2009 and 2017, we retrospectively reviewed pyeloplasty cases for treatment of UPJO in infants at three academic institutions. The primary outcome was success. Secondary outcomes were UPJO recurrence, complications, and operative time as a surrogate of skill acquisition. Continuous variables were analyzed by t test, Welch-test, and one-way ANOVA. Non-continuous variables were analyzed by Chi-squared test or Fisher's exact test. Learning curves (LC) were studied by r-to-z transformation and CUSUM.

RESULTS

Thirty-nine OP, 26 LP, and 39 RAL-P had mean operative times (OT) of 106, 121, and 151 min, respectively. LCs showed plateau in OT after 18 and 13 cases for LP and RAL-P, respectively. RAL-P showed a second phase of further improvements after 37 cases. At 16 months follow-up, there were similar rates of success and complications between the three groups.

CONCLUSIONS

Despite different duration of learning phases, proficiency was achieved in both LP and RAL-P as evidenced by stabilization of operative time and similar success rates and complications to OP. Before and after achievement of proficiency, LP and RAL-P can be safely learned and implemented for treatment of UPJO in infants.

Reconstructing a Nursing Skills Lab: A Quality Improvement Project

ABSTRACT

Safety is a paramount consideration when preparing nursing students for clinical practice. Skills lab traditions steeped in the rote memorization of procedures fail to bridge the gap between theory and practice, leaving patients at risk. The foundations of nursing skills lab curriculum in an associate degree nursing program was revised utilizing the Quality and Safety Education for Nurses and evidence-based teaching pedagogy to better prepare students for their first clinical experience. This article discusses how the skills lab curriculum was revised and examines how faculty felt the revisions impacted students' clinical performance outcomes related to safety and patient-centered care.

Optical cages made of graphitic frameworks

In pursuit of perfect infrared (IR) radiation absorbers, we examined quasi-crystal structures made of graphite wires. Simulations on an array of subwavelength graphitic cages and cage-within-cage frameworks indicate a flat absorption coefficient between 10-30 µm. The concept could be scaled up through the 50-120 µm [far-IR, terahertz (THz)] region by a proper structural design. For cage-within-cage, the IR radiation energy is funneled toward the inner cage, resulting in a rather hot structure. At longer wavelengths (microwave region), the electrical conductivity dominates the negative dielectric effect, and experiments with copper cages indicate scattering resonances. Graphitic structures allude to some absorption even at microwave frequencies. Applications are envisioned as anti-fogging surfaces, adaptable electromagnetic shields, energy harvesting, and efficient absorbers in the far-IR (THz frequencies).

Joint Sentinel-1 and SMAP data assimilation to improve soil moisture estimates

SMAP (Soil Moisture Active and Passive) radiometer observations at ~40 km resolution are routinely assimilated into the NASA Catchment Land Surface Model to generate the 9-km SMAP Level-4 Soil Moisture product. This study demonstrates that adding high-resolution radar observations from Sentinel-1 to the SMAP assimilation can increase the spatio-temporal accuracy of soil moisture estimates. Radar observations were assimilated either separately from or simultaneously with radiometer observations. Assimilation impact was assessed by comparing 3-hourly, 9-km surface and root-zone soil moisture simulations with in situ measurements from 9-km SMAP core validation sites and sparse networks, from May 2015 to December 2016. The Sentinel-1 assimilation consistently improved surface soil moisture, whereas root-zone impacts were mostly neutral. Relatively larger improvements were obtained from SMAP assimilation. The joint assimilation of SMAP and Sentinel-1 observations performed best, demonstrating the complementary value of radar and radiometer observations.

Evaluating soil moisture retrievals from ESA's SMOS and NASA's SMAP brightness temperature datasets

Two satellites are currently monitoring surface soil moisture (SM) using L-band observations: SMOS (Soil Moisture and Ocean Salinity), a joint ESA (European Space Agency), CNES (Centre national d'études spatiales), and CDTI (the Spanish government agency with responsibility for space) satellite launched on November 2, 2009 and SMAP (Soil Moisture Active Passive), a National Aeronautics and Space Administration (NASA) satellite successfully launched in January 2015. In this study, we used a multilinear regression approach to retrieve SM from SMAP data to create a global dataset of SM, which is consistent with SM data retrieved from SMOS. This was achieved by calibrating coefficients of the regression model using the CATDS (Centre Aval de Traitement des Données) SMOS Level 3 SM and the horizontally and vertically polarized brightness temperatures (TB) at 40° incidence angle, over the 2013 - 2014 period. Next, this model was applied to SMAP L3 TB data from Apr 2015 to Jul 2016. The retrieved SM from SMAP (referred to here as SMAP_Reg) was compared to: (i) the operational SMAP L3 SM (SMAP_SCA), retrieved using the baseline Single Channel retrieval Algorithm (SCA); and (ii) the operational SMOSL3 SM, derived from the multiangular inversion of the L-MEB model (L-MEB algorithm) (SMOSL3). This inter-comparison was made against in situ soil moisture measurements from more than 400 sites spread over the globe, which are used here as a reference soil moisture dataset. The in situ observations were obtained from the International Soil Moisture Network (ISMN; https://ismn.geo.tuwien.ac.at/) in North of America (PBO_H2O, SCAN, SNOTEL, iRON, and USCRN), in Australia (Oznet), Africa (DAHRA), and in Europe (REMEDHUS, SMOSMANIA, FMI, and RSMN). The agreement was analyzed in terms of four classical statistical criteria: Root Mean Squared Error (RMSE), Bias, Unbiased RMSE (UnbRMSE), and correlation coefficient (R). Results of the comparison of these various products with in situ observations show that the performance of both SMAP products i.e. SMAP_SCA and SMAP_Reg is similar and marginally better to that of the SMOSL3 product particularly over the PBO_H2O, SCAN, and USCRN sites. However, SMOSL3 SM was closer to the in situ observations over the DAHRA and Oznet sites. We found that the correlation between all three datasets and in situ measurements is best (R > 0.80) over the Oznet sites and worst (R = 0.58) over the SNOTEL sites for SMAP_SCA and over the DAHRA and SMOSMANIA sites (R= 0.51 and R= 0.45 for SMAP_Reg and SMOSL3, respectively). The Bias values showed that all products are generally dry, except over RSMN, DAHRA, and Oznet (and FMI for SMAP_SCA). Finally, our analysis provided interesting insights that can be useful to improve the consistency between SMAP and SMOS datasets.

Activation and maturation of alloreactive CD4-independent, CD8 cytolytic T cells

The goal of this study was to determine the in vivo conditions that promote activation of the (CD4-independent) CD8+ T cell-mediated rejection pathway. We have previously noted that hepatocellular but not islet allografts readily activate this rejection pathway. In the current study, we utilized these two cell transplant models to investigate whether differences in host cell recruitment to the graft site, expression of T-cell activation markers by CD8+ graft infiltrating cells (GICs), and/or development of delayed-type hypersensitivity (DTH) and cytotoxic T lymphocyte cell-mediated effector functions could account for the differential transplant outcomes. The collective results demonstrate that recruitment of CD8+ T cells to the site of transplant, CD103 or CD69 expression on CD8+ GICs, and activation of alloreactive DTH responses are insufficient to initiate CD4-independent, CD8-dependent transplant rejection. Instead, rejection by alloreactive (CD4-independent) CD8+ T cells correlated with expression of CD25, CD154 and CD43 by CD8+ GICs, in vitro alloproliferation by recipient CD8+ T cells, and the development of in vivo allospecific cytolytic effector function. These results suggest that tissue-derived factors influence the activation and maturation of (CD4-independent) CD8+ T cells into cytolytic effectors, which correlates with transplant rejection.

Prosodic facilitation in the resolution of syntactic ambiguities in subjects with left and right hemisphere damage

The purpose of this study was to determine if prosody facilitates the comprehension of sentences containing temporary syntactic ambiguities in control, and left (LHD) and right hemisphere damaged (RHD) subjects. To test for effects of prosodic facilitation, sentences were created where prosodic boundaries coincided with (cooperating), were absent (baseline), or conflicted (conflicting) with syntactic boundaries in three response times (RTs) experiments. Despite differences in overall RTs and response accuracy for each group, all three groups responded faster and more accurately to sentences in the cooperating than in the baseline and conflicting conditions across experiments, indicating that prosody facilitates syntactic parsing in brain-damaged subjects just as it does with normal control subjects. Results are discussed in relation to psycholinguistic theories of syntactic parsing and neurolinguistic theories of hemispheric specialization in processing the acoustic properties of prosodic structures.

Small incision cataract surgery and placement of posterior chamber intraocular lenses in patients with diabetic retinopathy

BACKGROUND AND OBJECTIVE

Diabetic patients undergoing cataract surgery have been demonstrated to have a guarded prognosis. Small incision cataract surgery has been postulated to cause fewer complications than other techniques of cataract extraction. We looked at small incision cataract surgery to see how diabetics fared.

PATIENTS AND METHODS

One hundred fifty-four eyes of diabetic patients were evaluated preoperatively through dilated fundus examination and Snellen visual acuity. The eyes then underwent small incision cataract surgery and were followed, undergoing periodic ophthalmoscopy, Snellen visual acuity measurement and additional postoperative therapeutic and surgical intervention.

RESULTS

Final visual acuity improved by two Snellen lines or more in 61 out of 154 (40%) eyes. Final visual acuity worsened in 38 out of 154 (25%) eyes.

CONCLUSIONS

Our results are similar to those reported for extracapsular surgery and phacoemulsification, suggesting that the prognosis is guarded for diabetics, even when undergoing small incision cataract surgery.

Reward dependence is positively related to urinary monoamines in normal men

According to Cloninger, three major personality dimensions, novelty seeking, harm avoidance, and reward dependence, are dependent on central monoaminergic systems. This study examined the relationship between the urinary levels of different monoamines and the above personality dimensions. Fifty normal men answered the Tridimensional Personality Questionnaire (TPQ); their levels of dopamine, norepinephrine, epinephrine, normetanephrine, metanephrine, 3-methoxy-4-hydroxyphenylglycol, vanilmandelic acid, homovanilic acid, and serotonin metabolite 5-hydroxyindolacetic acid were measured in urine on two consecutive nights. Significant and positive correlations were found between reward dependence, 3-methoxy-4-hydroxyphenylglycol, and epinephrine (r = .50 and r = .51, respectively). Monoamine levels explained 44% of the variance of reward dependence. Cluster analysis identified three groups of subjects presenting specific patterns of monoamine excretion. The TPQ scores could discriminate among subjects belonging to these clusters. These results point out a narrow relationship between urinary monoamine excretion and the basic personality dimension of reward dependence.

Ultrasound-guided cryotherapy for retinal tears in patients with vitreous hemorrhage

BACKGROUND AND OBJECTIVE

The goal was to utilize ultrasound-guided cryotherapy as an immediate, low-risk, noninvasive, precise method of treating retinal tears obscured by vitreous hemorrhage.

PATIENTS AND METHODS

Eleven patients with sudden onset of vitreous hemorrhage were referred for diagnosis and management. Ophthalmoscopy with scleral depression was unsuccessful at localizing peripheral retinal tears, and all of the patients were examined with ultrasound using the techniques of standardized echography. The cryoprobe was positioned for cryotherapy using both transverse and longitudinal B-scan approaches following the indentation of the globe as it appeared on the oscilloscope.

RESULTS

On follow-up examination after the vitreous hemorrhage cleared, 10 of the 11 tears were examined by ophthalmoscopy and were thought to have been adequately treated. One patient had a retinal detachment after remaining stable for 3 months. Two patients were treated with laser to enhance the cryotherapy seal. One patient was observed by another physician and underwent vitrectomy due to vitreous hemorrhage that persisted 2 months following cryotherapy. After vitrectomy, the physician reported a successful cryotherapy reaction at the treated tear. One final patient in the series required vitrectomy and scleral buckle before the hemorrhage had cleared, and the treatment did not appear to be complete.

CONCLUSION

Ultrasound-guided cryotherapy provides a noninvasive, inexpensive treatment alternative for retinal tears obscured by vitreous hemorrhage.

Lower sex hormones in men during anticipatory stress

Free cortisol, luteinizing hormone (LH), total testosterone and monoamines were measured in two successive nocturnal urine collections in 50 healthy men to assess the influence of anticipatory stress. The first collection (N-2) was two nights before and the second (N-1) was just on the night before a one-day experimental stressor consisting of participation in a one-day clinical research protocol. The mean cortisol level increased from 23.4 (N-2) to 66.6 micrograms (N-1), while mean LH level decreased from 2.68 (N-2) to 1.71 IU (N-1) and the mean testosterone level fell from 1.31 (N-2) to 0.70 microgram (N-1). There were no changes in monoamines. Inhibition of sex hormones is a relatively neglected area of stress research.

Caloric restriction and spatial learning in old mice

Spatial learning in old mice (19 or 24 months old), some of which had been calorically restricted beginning at 14 weeks of age, was compared to that of young mice, in two separate experiments using a Morris water maze. In the first experiment, only old mice reaching criterion performance on a cued learning task were tested in a subsequent spatial task. Thus, all old mice tested for spatial learning had achieved escape latencies equivalent to those of young controls. Despite equivalent swimming speeds, only about half the old mice in each diet group achieved criterion performance in the spatial task. In the second experiment, old and young mice all received the same number of training trials in a cued task and then in a spatial task. Immediately following spatial training, they were given a 60-s probe trial, with no platform in the pool. Both groups of old mice spent significantly less time in the quadrant where the platform had been and made significantly fewer direct crosses over the previous platform location than did the young control group. As in Experiment 1, calorie restriction failed to provide protection against aging-related deficits. However, in both experiments, some individual old mice evidenced performance in spatial learning indistinguishable from that of young controls. Separate comparisons of "age-impaired" and "age-unimpaired" old mice with young controls may facilitate the identification of neurobiological mechanisms underlying age-related cognitive decline.

Day-to-day intraindividual reliability and interindividual differences in monoamines excretion

The urine of 44 normal men was collected during 2 nights to evaluate components of biological variation, i.e., intraindividual day-to-day variability and interindividual variability in monoamines excretion. Monoamines presented important interindividual variability [interindividual coefficients of variation (%): dopamine 18.3, norepinephrine 66.7, epinephrine 85.3, normetanephrine 22.4, metanephrine 76.8, 3-methoxy-4-hydroxyphenylglycol (MHPG) 77.0, vanilmandelic acid (VMA) 64.3, homovanilic acid (HVA) 71.3, 5-hydroxyindolacetic acid (5-HIAA) 20.4]. The reliability of these amounts was high, with intraclass correlation coefficients ranging from 0.43 (P < 0.001) for MHPG free form to 0.65 (P < 10(-6)) for dopamine and normetanephrine (intraindividual coefficients of variation (%): dopamine 8.5, norepinephrine 39.9, epinephrine 45.9, normetanephrine 10.3, metanephrine 46.3, MHPG 37.5, VMA 30.7, HVA 41.0, 5-HIAA 12.3).

Aging does not affect steady-state expression of the Na+/Ca2+ exchanger in rat brain

1. Steady-state protein and mRNA levels of the Na+/Ca2+ exchanger were studied in old (24-month) and young (3-month) brains of male Fischer 344 rats by Western and Northern analysis. 2. Northern analysis with a cDNA proble for the Na+/Ca2+ exchanger amplified from human brain RNA indicated the presence of two transcripts for the Na+/Ca2+ exchanger (6 and 16 kb). Both transcripts were present in similar abundance in the cerebrum and hippocampus. In the cerebellum the 6-kb transcript predominated. The cerebellum had the highest overall level of expression. There were no significant age-related effects seen on the level of expression of either transcript in each of the brain areas tested. 3. Western analysis of plasma membrane vesicles purified from cerebral cortex identified a single protein of 116 kDa. Consistent with the Northern analysis, no age-related effect on protein levels was seen. 4. The mechanisms underlying altered Na+/Ca2+ exchange activity in aging rat brain (Michaelis, 1989) most likely do not involve changes in gene expression and are therefore more likely to represent posttranslation modifications of the protein.

Colitis cystica profunda: diagnosis and management

We have reported a case of colitis cystica profunda, an uncommon, benign disease of the colon presumably due to chronic inflammation, characterized by submucosal mucus-filled cysts. It may be premalignant, having been associated with ulcerative colitis and rectal adenocarcinoma. Diagnosis requires a high degree of suspicion and adequate biopsies, and treatment is by simple excision.

Role of gastrin and gastrin receptors on the growth of a transplantable mouse colon carcinoma (MC-26) in BALB/c mice

We recently reported trophic response of transplantable mouse colon cancer cells (MC-26) to pentagastrin, in vivo, and demonstrated gastrin receptors on MC-26 cells, in vitro. In the present study, growth of MC-26 cells in mice, in response to pentagastrin, was studied in relation to binding kinetics and capacity of gastrin receptor. Gastrin receptor levels on mouse fundic and colonic membranes and on MC-26 cellular membranes were determined before MC-26 cell inoculation and designated as Day 0 levels. Four groups of mice were next inoculated with MC-26 cells and given injections of either pentagastrin (treated) or normal saline (control) for 10 or 15 days. At the end of the treatment periods, body, tumor, fundic, and colon weights were noted and gastrin receptor measured. tumor and fundic weights increased significantly within 15 days of pentagastrin treatment, compared to control values. In control (non-pentagastrin treated) mice, the binding affinity of gastrin receptor on tumor membranes was significantly decreased and associated with the complete loss of high-affinity gastrin receptor (Kd = less than 0.5 nM) by Day 15 of tumor growth. On the other hand, both the binding affinity and gastrin receptor levels of tumor membranes were maintained at Day 0 values by pentagastrin treatment. Endogenous gastrin was therefore ineffective in maintaining high-affinity gastrin receptor on control tumors. A significant number of low-affinity gastrin-binding sites (Kd = less than 2 nM) appeared in control tumors by Day 15, which could reflect rapid dedifferentiation or conformational changes of gastrin receptor in the absence of high levels of normal regulatory hormones. These studies demonstrate that the trophic effects of gastrin on MC-26 cells are probably mediated by its regulation and maintenance of the binding affinity and capacity of gastrin receptor on the cancer cells, in vivo.

The effect of aging on the growth of colon cancer

Reports on the effect of patient age on the prognosis for colon cancer vary. We have tested the effect of aging using a model of murine colon adenocarcinoma in groups of mice of different ages. In experiment A, Balb/c mice of age groups 3-4 weeks, 10-12 weeks, 24-32 weeks and 40-48 weeks (13 mice/group) were injected with 5 X 10(4) MC-26 cells subcutaneously in the right flank. Tumors were measured twice weekly, and the rate of occurrence of tumor, mortality rate, and growth rate were calculated. In experiment B, the same plan as experiment A was used, except mice of age groups I (14 days), II (3-4 weeks), and III (20-22 months) were used with tumor doses of 1 X 10(4) cells and 5 X 10(5) cells (9-15 mice/group). In both experiments, the rate of growth of tumor, mortality rate, and sizes of tumors obtained were the same. In experiment A, the rate of occurrence of the tumors was the same in all groups, but in experiment B the occurrence of the tumor varied. A palpable tumor appeared earliest in the weanling mice (14 days), next in old mice (20-22 months), and last in the young adult group (3-4 weeks). Tumor doubling time was longest in the young adult mice (7 days), intermediate in the old mice (6.1 days), and shortest in the weanling mice (5.5 days). Established tumors grew at similar rates (as assessed by doubling time), independent of host age. Mortality rates were similar.(ABSTRACT TRUNCATED AT 250 WORDS)

Effect of aging on gallbladder contraction and release of cholecystokinin-33 in humans

The objective of this study was to examine the effect of aging on gallbladder contraction and cholecystokinin (CCK) release, as well as on the correlation between the two in humans who are free of gallbladder disease. Twenty-nine human volunteers were divided into a young group of 14 individuals (ages 22 to 42 years, median age 32 years) and an older group of 15 individuals (ages 60 to 84 years, median age 66 years). In the study each person in both groups was given corn oil (Lipomul), 1.5 ml/kg, by mouth after an overnight fast. Blood was collected for measurement of CCK-33 by radioimmunoassay before and at intervals after ingestion of Lipomul. Simultaneous measurements of gallbladder volume were obtained by real-time varian ultrasonography. Both fasting and fat-stimulated concentrations of CCK in plasma were significantly higher in the older individuals than in the younger volunteers. The 60-minute integrated measurement of CCK release was significantly increased in the older people as compared with the young. Both fasting and maximally contracted gallbladder volumes were equal in the older and younger groups. The rate of emptying of the gallbladder was equal in both age groups, but the gallbladders of older people appeared to show an earlier initiation of contraction. The highly significant correlation of gallbladder contraction with levels of CCK was similar in both age groups, but the sensitivity of the gallbladder to CCK in the older people was significantly decreased. In conclusion, both fasting and fat-stimulated plasma levels of CCK increase with aging. The sensitivity of the gallbladder muscle to stimulation by CCK is diminished with age, but this appears, teleologically, to be matched by the increased release of CCK, so the kinetics of gallbladder emptying are little different in the aged.

Importance of the ileum in neurotensin released by fat

Neurotensin is a potent stimulant of pancreatic exocrine secretion. Ileal mucosa is the storage site for about 90% of total neurotensin. Release occurs rapidly after a fatty meal and during perfusion of the duodenum and jejunum with fat but not during perfusion of the ileum with fat. To determine the origin of neurotensin released after fat stimulation, we studied the pattern of release of neurotensin before and after resection of the distal two thirds of the small bowel. Six dogs with gastric and duodenal fistulas were studied on different days. All dogs received infusions (in random order) of intraduodenal corn oil (Lipomul) (3 ml/kg/hr) and intravenous calcium chloride (0.36 mmol/kg intravenous bolus, followed by 0.36 mmol/kg/hr infusion) before and 6 weeks after resection of the distal two thirds of the small bowel with preservation of the ileocecal valve. Plasma levels of neurotensin were measured by specific radioimmunoassay. We found that release of neurotensin, in response to both intraduodenal Lipomul and intravenous calcium chloride stimulation, was abolished by resection of the distal small bowel. Before surgery, Lipomul-stimulated release of neurotensin rose to a peak concentration of 51 +/- 17 pg/ml at 30 minutes. After surgery there was no release (the levels were unchanged from basal). Before surgery, intravenous calcium chloride produced a peak release of neurotensin (52 +/- 15 pg/ml) 2 minutes after bolus injection. After surgery, neurotensin was not released by intravenous calcium. We conclude that the source of neurotensin released by perfusion of the proximal gut and by intravenous calcium infusion is the ileum. The release of neurotensin from the distal gut appears to be dependent on a signal from proximal to distal gut. The identity of the signal is unknown but is either a nerve reflex or a peptide agent.

The role of neurotensin in human gallbladder motility

Gallbladder contraction in response to a fatty meal is thought to be caused by release of cholecystokinin (CCK). We have previously demonstrated a close correlation between circulating concentrations of CCK and contraction of the gallbladder in normal humans and in gallstone patients. Recent studies in animals, however, have shown that other potentially cholecystokinetic hormonal agents are released by a fatty meal, which suggests that other hormones may be involved in postprandial gallbladder contraction. Neurotensin, a 13-amino acid peptide, is released by fat; we have shown it to cause gallbladder contraction in dogs. In the present study, we measured release of neurotensin in seven normal adult volunteers. We determined the effects of infused neurotensin (4 pmol/kg-min) on gallbladder contractility, measured by ultrasonography in 10 adult volunteers, and we evaluated release of neurotensin in eight patients with gallstones. After ingestion of fat, we found significant release of neurotensin in normal volunteers from a mean basal concentration of 15.9 +/- 3.5 pg/ml to a maximum of 34.7 +/- 0.2 pg/ml. In the gallstone patients after fat ingestion, neurotensin rose from a basal of 16.8 +/- 3.1 pg/ml to a maximum of 53.4 +/- 28.1 pg/ml, which was a significantly greater release than in controls. Intravenous infusion of neurotensin produced dilatation of the gallbladder (from a mean basal volume of 13.7 +/- 2.3 cc to 20.0 +/- 1.8 cc). Neurotensin causes relaxation of the gallbladder in humans and, by contributing to stasis, may be involved in the formation of gallstones.

Indications for the use of parenteral H2-receptor antagonists

Development of acute mucosal ulceration is a complex series of catabolic interactions. Hospitalized patients with duodenal or gastric ulcer, pathologic gastric hypersecretory states (such as Zollinger-Ellison syndrome), gastric outlet obstruction, esophagitis, severe gastritis or duodenitis, sepsis, trauma (particularly head injury or burns), and some patients receiving high-dose corticosteroids are at risk of developing acute stress ulcers. Treatment should be initiated as soon as the patient is identified as being at risk, because measures designed to prevent bleeding or perforation are more effective than those designed to stop bleeding once it supervenes and the cascade of multiple organ failure commences. The presence of acid will trigger the onset of this condition; however, ulceration will not occur if the intraluminal pH can be maintained above 5 by periodic antacid treatment or by H2-receptor blockade. The dosing regimen of antacid or of H2-receptor antagonist should not be fixed, but should be sufficient to keep the gastric pH higher than 5. Antagonists administered via a nasogastric tube are the first line of defense, but 30 to 50 percent of the most ill patients will also be treated parenterally with H2-receptor antagonists. Parenteral H2-receptor blockade therapy is indicated in these patients when the risk of acute or continued ulceration of esophageal, gastric, or duodenal mucosa is high and the oral administration of medication is either not possible or the response to such therapy is unreliable. Parenteral H2-receptor antagonists are rarely administered alone.

Performance of laying hens subjected to intermittent lighting initiated at 24 weeks of age

Leghorn pullets of a commercial strain were subjected to a conventional light program of constant photoperiod or an intermittent programming involving, during the house of conventional "lights-on", 45 min light (L): 15 min dark (D) from 24 to 27 weeks of age; 30 min L:30 min D from 28 to 35 weeks; and 14 min L:45 min D from 36 weeks to the duration of the trial. Each light treatment was tested with 12 replicate groups of 14 individually caged birds housed in adjacent rooms, with all birds fed a standard 15% crude protein, 2750 kcal ME/kg diet. Intermittent lighting resulted in a significant (P less than .05) reduction in feed intake and a consistent but nonsignificant (P less than .05) reduction in egg production. Egg size, egg shell quality, and albumen quality, as assessed by Haugh units, were not affected by light treatment. Due to the effect on egg production, it is concluded that intermittent lighting programs should not be initiated close to time of peak egg production.

Uveal malignant melanoma in three generations of the same family

Three patients in three successive generations from the same family had choroidal malignant melanoma. The third generation patient had multiple primary malignancies; his siblings also had multiple malignancies. Chromosome studies of the third generation patient revealed no abnormality. To the best of our knowledge, this is the second such pedigree reported.

Self-produced locomotion restores visual capacity after striate lesions

Rats permitted unrestrained movement in a patterned visual environment during the interval between two-stage vilateral lesions of the visual cortex reacquire a preoperatively learned pattern discrimination. Rats passively transported through the identical visual environment do not. This is the first demonstration that interoperative self-produced locomotion is essential for recovery of function in the visual system.

Aging and the passage of L-tyrosine, L-DOPA, and inulin into mouse brain slices in vitro

The effect of age on active transport of catecholamine precursors was studied in a healthy population of mature (12-mo.-old) and senescent (30-mo.-old) C57BL/6J male mice. No age differences were observed in uptake of L-(3H)-tyrosine IN VITRO by slices of hypothalamus, brain stem, and striatum at external concentrations equal to or greater than blood levels. However, age-related reductions were observed intermittently in the hypothalamus, brain stem, and striatum at very low concentrations of tyrosine (less than 10 pg/ml). No age differences were observed in incorporation of L-(3H)-tyrosine into hypothalamic proteins when corrected for intracellular uptake of L-(3H)-tyrosine. No age differences were observed in uptake of L-(3H)-DOPA. The possible contribution of age-related changes in extra-cellular space to decreased uptake was determined to be negligible by wash-out studies of tyrosine and by the uptake of inulin. A significant age-related increase of inulin uptake IN VITRO was observed under ionic conditions which minimize tissue swelling.

Selective changes in the permeability of the blood-brain barrier after pharmacological or surgical deafferentation

Unilateral eye removal results in an increased delivery of blood-borne glucose, norepinephrine, choline, and tyrosine, but not of proline, to the denervated optic lobes. Administration of reserpine to chicks increases penetrance of norepinephrine into the brain but not of tyrosine, choline, or proline. Selective alterations in the permeability of the blood-brain barrier may represent a mechanism for the modulation of the delivery of critical nutrients to the brain.