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Biomedical subjects

R Rosenthal

Publications and source records attributed to R Rosenthal.

At least 19 recordsLinked to original sources
PubMed2003

Technical considerations in laparoscopic resection of gastric neoplasms.

BACKGROUND: The purpose of this study was to determine the use of different laparoscopic approaches in the management of gastric neoplasms based on tumor type and location. METHODS: We retrospectively reviewed the records of seven patients (3 men and 4 women) with 11 gastric lesions who were referred to our facility between March 2000 and October 2001 for laparoscopic excision of gastric neoplasms. RESULTS: Two patients had gastrointestinal stromal lesions (3 lesions); two patients had hyperplastic polyps (3 lesions); one patient had carcinoid tumor (2 lesions); one patient had a carcinoma in situ and an adenoma; and one patient had an ectopic pancreas. Extraluminal laparoscopic wedge resection was used in four patients with lesions at the anterior gastric wall or along the lesser or greater curvature. Intragastric excision was used in two patients with small posterior wall lesions, and a transgastrotomy approach was used in one patient with a posterior wall lesion that could not be removed by the intragastric approach. All the lesions were completely excised with clear margins. The median hospital stay was 3 days. Complications developed in two patients. One patient presented with a perforated ulcer 2 weeks after surgery, and a second patient had postoperative pyloric edema that resolved with conservative treatment. CONCLUSIONS: The use of different laparoscopic approaches based on gastric neoplasm type and location facilitates tumor access and resection.

Adenoma↗
PubMed2003

Determination of hemoglobin levels in the finger using near infrared spectroscopy.

We previously demonstrated that near-infrared spectroscopy can be used to measure blood flow. The spectrum of blood is dominated by hemoglobin. Therefore, it should be possible to determine the concentration of hemoglobin in tissue using near-infrared transmittance. We attempted to do this in the finger using a unique handheld multiple wavelength spectrophotometer. We took samples from 73 subjects and performed repeat measurements in several subjects. Hemoglobin level was determined at the time of near-infrared measurement. We performed correlation analysis between the hemoglobin values and the absorbance values. There was a strong correlation between hemoglobin levels and the 14 wavelengths (r = 0.738, n = 121, SEE = 1.7). We categorized the patients by hemoglobin level as either normal (12-16 g/dl), mildly anemic (10-12 g/dl), or moderately anemic (<10 g/dl). There were 21 patients in the low hemoglobin group, 29 in the middle range, and 23 in the normal range. The mean hemoglobin levels were 8.4 +/- 0.3 g/dl for the low group, 10.9 +/- 0.1 g/dl for the mildly anemic group, and 13.8 +/- 0.3 g/dl for the group with normal hemoglobin. There was a clear separation of absorbance values among the three groups. The major differences seen were in the midrange of the spectrum. It is encouraging that this first study of hemoglobin measurement yielded data permitting a discrimination of hemoglobin levels. It is hoped that future refinements will lead eventually to a non-invasive technique for the measurement of blood hemoglobin concentration.

Anemia↗
PubMed2002

Laparoscopic total mesorectal excision.

After total mesorectal excision for rectal cancer was introduced in 1982, local recurrence rates decreased to 5%. These results were found to be reproducible; therefore, the technique became standard for the treatment of rectal cancer. Laparoscopic surgery for curable colorectal malignancy is still considered investigational. Indeed, the United States National Cancer Institute (NCI) trial excludes rectal carcinoma. The application of laparoscopy to rectal carcinoma must compete with total mesorectal excision, which has obtained favorable results in the last decade. In this review, we assess the adequacy of laparoscopic total mesorectal excision, describe the techniques (both anterior resection and abdominoperineal resection), and discuss their potential advantages.

Abdomen↗
PubMed2002

Intestinal ischemia after bushmaster (Lachesis muta) snakebite--a case report.

After a snakebite by the Costa Rican bushmaster Lachesis stenophrys, a 64-year-old patient developed cardiovascular shock and coagulopathy. After intensive care and antivenom treatment, he was discharged after 4 days but had to be hospitalised again 3 days later because of abdominal pain and bowel obstruction. An emergency laparotomy revealed a necrotic ileum and caecum, and an obstruction of the superior mesenteric artery. Until now, this type of intestinal ischemic complication after a snakebite has not been reported in the literature. The effects of bushmaster venom are discussed.

Animals↗
PubMed2002

[Laparoscopic and conventional cholecystectomy. Didactic concept for training and introduction of laparoscopic cholecystectomy and preventing complications].

AIM: This study has assessed the suitability of an educational concept for the introduction and training of laparoscopic cholecystectomy, a newly established operational procedure, within an university teaching hospital with a large number of surgeons. PATIENTS AND METHODOLOGY: Since introduction of the first laparoscopic cholecystectomy all cholecystectomies were prospectively assessed over a period of two years (from May 1990 till May 1992). The educational concept applied was such that a given surgeon would first receive training from an instructor for 15 procedures and then assume responsibility for instruction of a subsequent trainee. RESULTS: In two years 355 patients underwent cholecystectomy. 60% of the operations were performed laparoscopically and 40% of the operations performed openly. During the two year period 13 surgeons were trained in the new technique, with an average of 16 operations per surgeon. Throughout the introductory phase there were no serious complications, and in particular no damage to the bile duct. DISCUSSION: The advantage of this introductory training phase has repeatedly been subject of discussion in the literature. In the meanwhile guidelines from specialist bodies and national institutions exist for regulating the education of new surgical techniques. In the past few years introduction to new techniques has gradually shifted toward training on the skill-stations and virtual reality trainers. CONCLUSION: The described educational concept for the introduction and training of laparoscopic cholecystectomy has been well approved and accepted since the early 90's.

Cholecystectomy↗
PubMed2001

The relationship of depression and stressors to immunological assays: a meta-analytic review.

This is a broad meta-analysis of the relations of both depression and stressors to immunological assays. The number of study samples (greater than 180) and measures (greater than 40) is much more extensive than any so far. Analyses are done by both fixed and random effects. By a fixed-effects analysis, both major depression and naturally occurring acute stressors are associated with (1) an overall leukocytosis, (2) mild reductions in absolute NK-cell counts and relative T-cell proportions, (3) marginal increases in CD4/CD8 ratios, and (4) moderate decreases in T- and NK-cell function. However, the degree of heterogeneity of the studies' results raises questions about their robustness. Therefore, we also did the first random effects analysis to estimate what is likely to appear in future studies. For depression, the analysis showed the immunological correlates included (1) an overall leukocytosis, manifesting as a relative neutrophilia and lymphoenia; (2) increased CD4/CD8 ratios; (3) increased circulating haptoglobin, PGE(2), and IL-6 levels; (4) reduced NK-cell cytotoxicity; and (5) reduced lymphocyte proliferative response to mitogen. For stressors, the random effects analysis showed that future studies are likely to find the following effects: (1) an overall leukocytosis, manifesting as an absolute lymphocytosis; (2) alterations in cytotoxic lymphocyte levels, CD4/CD8 ratios, and natural killer cell cytotoxicity with the direction of change depending on the chronicity of the stressor; (3) a relative reduction of T-cell levels; (3) increased EBV antibody titers; (4) reduced lymphocyte proliferative response and proportion of IL-2r bearing cells following mitogenic stimulation; and (5) increased leukocyte adhesiveness. The random-effects analysis revealed that for both major depression and naturally occurring stressors the following effects are shared: leukocytosis, increased CD4/CD8 ratios, reduced proliferative response to mitogen, and reduced NK cell cytotoxicity. The implications for these findings for disease susceptibility and the pathophysiology of these conditions is discussed.

Biomarkers↗
PubMed2001

A prospective randomized trial of different laparoscopic gastric banding techniques for morbid obesity.

BACKGROUND: Slippage of the stomach is the most common postoperative complication after laparoscopic adjustable silicone gastric banding (LASGB) for morbid obesity. Retrogastric placement (RGP) of the band through the lesser sac can cause posterior slippage Incomplete suturing often is responsible for anterior slippage. A randomized prospective study was constructed to determine whether laparoscopic esophagogastric placement (EGP) is associated with a lower incidence of postoperative slippage and pouch dilation than RGP. METHODS: Morbid obese patients presenting for LASGB were randomized to undergo either an EGP (n = 50) or an RGP (n = 51). Patients were blinded to which procedure they underwent, and follow-up date were obtained by a blinded independent investigator. Standardized clinical and radiologic controls were used to assess pouch enlargement and slippage. RESULTS: Operating time was similar for the two procedures (54.5 min for EGP vs 58 min for RGP). There was no significant difference in postoperative weight loss (34 kg after EGP vs 37 kg after RGP within 12 months), esophagus dilation, or postoperative quality of life. There were two postoperative slippages and one pouch dilation in the RGP group and no postoperative complication in the EGP group. CONCLUSIONS: The placement of a LAP-BAND adjustable gastric banding system by the EGP technique is safe and results in a lower frequency of postoperative complications than its placement by the RGP technique. Clear anatomic landmarks are a benefit to education and to the learning curve for LASGB.

Adolescent↗
PubMed2001

[Video-laparoscopic placement of adjustable gastric banding (lap-band) in the treatment of morbid obesity. Preliminary results after 407 interventions].

INTRODUCTION: Morbid obesity is the most frequent nutritional disorder in developed countries. Bariatric surgery is one option for the definitive treatment of this disorder. We present 407 patients who underwent implantation of adjustable silicone gastric banding. Ninety-four percent of the patients were satisfied with the procedure and its results. MATERIAL AND METHOD: We performed a retrospective study in the Surgery Department of the Nordwestkrankenhaus teaching hospital of the University of Frankfurt. From April 1996 to January 2000 we performed laparoscopic placement of adjustable silicone gastric banding in 407 patients, using Kuzmak's technique. Mean body mass index was 49.1 and mean weight was 139.2 kg. We describe the patient selection method and provide a detailed description of the technique and its possible problems. RESULTS: There was no operative or postoperative mortality. None of the patients required conventional surgery. Mean operating time was 62 minutes (including operating times during the learning period). Mean hospital stay was 5 days. We performed 24 (5,89%) reinterventions: 11 for displacement, 2 for erosion, 4 for infection of the reservoir, 2 due to review of the reservoir to prevent penetration and 4 due to dilatations of the pouch (changing the banding from a retrogastric to a retroesophageal position); one patient requested removal of the banding. Follow-up was performed at months 1, 6, 9 and 12. Mean weight loss was 28 kg at 6 months and 54 kg at 1 year. Mean weight loss in patients followed-up for 2 years was 58 kg. A total of 94.9% of the patients were satisfied with the procedure. CONCLUSIONS: Laparoscopic implantation of adjustable gastric banding (Lap-Band) combines the aims of conventional gastroplasty with the advantages of laparoscopic surgery in terms of postoperative morbidity and minimal invasiveness.

Adult↗
PubMed2001

[Post-traumatic pancreatic pseudocyst in a child].

Pancreatic pseudocysts are rare in children. Traumatic injury accounts for 80% of the cases. We present the case of a pancreatic injury with pseudocyst formation in a child and discuss the initial management of pancreatic injury as well as the treatment of pseudocyst formation in children.

Abdominal Injuries↗
PubMed2001

Meta-analytic methods, the Rorschach, and the MMPI.

In response to concerns described by H. N. Garb, J. M. Wood, M. T. Nezworski, W. M. Grove, and W. J. Stejskal (2001), the authors present the weighted and unweighted means and medians of the effect sizes obtained by J. B. Hiller, R. Rosenthal, R. F. Bornstein, D. T. R. Berry, and S. Brunell-Neuleib (1999). These indices of central tendency are presented separately for Minnesota Multiphasic Personality Inventory (MMPI) and Rorschach effect sizes, both for all the studies in the meta-analysis and for a 10% trimmed sample designed to obtain more robust estimates of central tendency. The variability of these 4 indices is noticeably greater for the MMPI than for the Rorschach. Meta-analysts must compute, compare, and evaluate a variety of indices of central tendency, and they must examine the effects of moderator variables. The authors also comment briefly on the use of phi versus kappa, combining correlated effect sizes and possible hindsight biases.

Humans↗
PubMed2001

Why introverts can't always tell who likes them: multitasking and nonverbal decoding.

Despite personality theories suggesting that extraversion correlates with social skill, most studies have not found a positive correlation between extraversion and nonverbal decoding. The authors propose that introverts are less able to multitask and thus are poorer at nonverbal decoding, but only when it is a secondary task. Prior research has uniformly extracted the nonverbal decoding from its multitasking context and, consequently, never tested this hypothesis. In Studies 1-3, introverts exhibited a nonverbal decoding deficit, relative to extraverts, but only when decoding was a secondary rather than a primary task within a multitasking context. In Study 4, extraversion was found to correlate with central executive efficiency (r = .42) but not with storage capacity (r = .04). These results are discussed in terms of arousal theories of extraversion and the role of catecholamines (dopamine and norepinephrine) in prefrontal function.

Arousal↗
PubMed2001

Athletes with lower limb ischaemia.

The case of a young healthy sportsman and acute exacerbation of chronic infragenicular pain is presented. Further investigation revealed an obstruction of the tibiofibular trunk due to an osteochondroma, arising from the fibula, which was immediately resected. Osteochondroma is observed in 1-2% of the population and may present with vascular complications. In young patients and athletes, leg pain may be of vascular origin due to an entrapment or compression and should always be considered.

Adult↗
PubMed2001

Fibroblast growth factor receptor 2 (FGFR2) in brain neurons and retinal pigment epithelial cells act via stimulation of neuroendocrine L-type channels (Ca(v)1.3).

In contrast to the fibroblast growth factor receptor 1 (FGFR1), little is known about intracellular signaling of FGFR2. The signaling cascade of FGFR2 was studied using the perforated patch configuration of the patch-clamp technique in cultured rat retinal pigment epithelial (RPE) cells that express both FGFR1 and FGFR2. Interaction of signaling proteins was studied using immunoprecipitation techniques with membrane proteins from RPE cells and freshly isolated rat brain. When Ba(2+) currents through L-type channels were studied, extracellular application of bFGF (10 ng/ml) led to a shift of the steady-state activation to more negative values. In 50% of cells, an additional increase in maximal current amplitude was observed. This effect was blocked by the tyrosine kinase inhibitor lavendustin A (10(-5) M) but was not influenced by the FGFR1 blocker SU5402 (2 x 10(-5) M) or by the blocker for src-kinase herbimycin A (10(-5) M). Immunoprecipitation of FGFR2 led to coprecipitation of alpha 1D Ca(2+) channel subunits and precipitation of alpha 1D subunits led to coprecipitation of FGFR2. Immunoprecipitation of FGFR1 did not result in the coprecipitation with alpha 1D Ca(2+) channel subunits. The coprecipitation results were comparable when using brain tissue and RPE cells. The alpha 1D subunit-specific band were stained with antiphosphotyrosine antibodies. We conclude that FGFR2 acts via a different signaling cascade than FGFR1. This cascade involves an src-kinase-independent, close functional interaction of FGFR2 and the alpha subunit of neuroendocrine L-type channels.

Animals↗
PubMed2001

Meta-analysis: recent developments in quantitative methods for literature reviews.

We describe the history and current status of the meta-analytic enterprise. The advantages and historical criticisms of meta-analysis are described, as are the basic steps in a meta-analysis and the role of effect sizes as chief coins of the meta-analytic realm. Advantages of the meta-analytic procedures include seeing the "landscape" of a research domain, keeping statistical significance in perspective, minimizing wasted data, becoming intimate with the data summarized, asking focused research questions, and finding moderator variables. Much of the criticism of meta-analysis has been based on simple misunderstanding of how meta-analyses are actually carried out. Criticisms of meta-analysis that are applicable are equally applicable to traditional, nonquantitative, narrative reviews of the literature. Much of the remainder of the chapter deals with the processes of effect size estimation, the understanding of the heterogeneity of the obtained effect sizes, and the practical and scientific importance of the effect sizes obtained.

Humans↗
PubMed2000

[Pheochromocytoma: diagnosis and treatment].

Phaeochromocytoma is a rare tumour which produces a variety of symptoms. The most important factor is to think of the diagnosis, and there are many biochemical and pharmacological tests as well as radiological procedures to confirm it. Once the phaeochromocytoma is localised, it should, if possible, be removed. Surgery is the treatment of choice. In 1972 Ross described the diagnosis and therapy as "think of it, confirm it, find it and remove it". Today, 28 years later, this paper reviews the diagnosis and therapy of phaeochromocytoma under these key headings.

Adrenal Gland Neoplasms↗
PubMed2000

Activation of neuroendocrine L-type channels (alpha1D subunits) in retinal pigment epithelial cells and brain neurons by pp60(c-src).

The aim of this study is to characterize the subtype of tyrosine kinase-regulated L-type Ca(2+) channels in retinal pigment epithelial (RPE) cells. Ca(2+) channel alpha1D-subunits were enriched by immunoprecipitation from membrane proteins isolated from rat RPE cells. Western blot analysis of the precipitates revealed coprecipitation of pp60(c-src). In addition, in precipitates obtained with antibodies against pp60(c-src), alpha1D-subunits were identified. The same was observed in immunoprecipitations from rat brain neurons. Tyrosine phosphorylation of alpha1D-subunits was confirmed using anti-phosphotyrosine antibodies. Ba(2+) currents through L-type channels in cultured rat RPE cells were increased by intracellular application of active pp60(c-src) (30 U/ml) (heat-inactivated pp60(c-src) had no effect). Thus, L-type channels of the neuroendocrine subtype can be expressed in epithelial cells and are activated by tyrosine kinase of the src subtype. This kind of regulation is also suggested for brain-derived neurons.

Animals↗
PubMed2000

Contrasts and correlations in effect-size estimation.

This article describes procedures for presenting standardized measures of effect size when contrasts are used to ask focused questions of data. The simplest contrasts consist of comparisons of two samples (e.g., based on the independent t statistic). Useful effect-size indices in this situation are members of the g family (e.g., Hedges's g and Cohen's d) and the Pearson r. We review expressions for calculating these measures and for transforming them back and forth, and describe how to adjust formulas for obtaining g or d from t, or r from g, when the sample sizes are unequal. The real-life implications of d or g calculated from t become problematic when there are more than two groups, but the correlational approach is adaptable and interpretable, although more complex than in the case of two groups. We describe a family of four conceptually related correlation indices: the alerting correlation, the contrast correlation, the effect-size correlation, and the BESD (binomial effect-size display) correlation. These last three correlations are identical in the simple setting of only two groups, but differ when there are more than two groups.

Analysis of Variance↗