Tumor model for laparoscopy in pediatric oncology: subperitoneal inoculation of human hepatoblastoma cells in nude rats.

BACKGROUND: Minimally invasive surgery (MIS) for diagnostic or even ablative purposes in pediatric oncology is gradually evolving, but little is known about its biological consequences and surgical complications. Especially for hepatoblastoma (HB), no study on the influence of laparoscopy is available yet. A special tumor model could facilitate a variety of investigations. The present study introduces a laparoscopic technique to create subperitoneal metastases of human HB. METHODS: 7 immuno-incompetent (rnu/rnu) rats (mean weight 198 g) received a stab incision in the lower abdomen to insert a 4 mm scope. Under laparoscopic guidance (CO2 pressure of 1 mmHg, flow of 0.2 l/min) an 18 G needle was introduced, to inject several subperitoneal deposits of the tumor cell suspension (HuH6, 3 x 10 (6) in 1 ml of RPMI-1640 medium). Tumor growth was allowed for 6 - 7 weeks and finally the animals were laparoscopically evaluated for peritoneal metastases. Each suspicious lesion was harvested for histology. RESULTS: One animal was investigated after 6 weeks without evidence of tumor growth. After 7 weeks, in 4 out of 6 animals at least one lesion could be detected. Histology revealed HB in all specimens. CONCLUSION: Subperitoneal inoculation of human HB cells in nude rats achieves intraabdominal tumor growth. The present model allows a variety of laparoscopic strategies and their oncological impact to be studied. Thus it may contribute to the development of distinct oncological concepts for MIS in children with HB.

Videoscopic fluorescence diagnosis of peritoneal and thoracic metastases from human hepatoblastoma in nude rats.

BACKGROUND: Various medical disciplines are employing photodynamic diagnosis (PDD) when searching for malignancies. It is still unknown whether pediatric solid tumors such as hepatoblastoma are susceptible to this technique as well. METHODS: Human hepatoblastoma cells were injected into the abdomen or right thoracic cavity of nude rats. Tumor growth was allowed for 7 weeks. Then, photosensitization was induced by peritoneal lavage with 5-aminolevulinic acid (ALA). Applying the Storz PDD system and one 4-mm scope, all animals were investigated by videoscopic white light diagnosis (WD) and PDD. Suspicious lesions were marked and analyzed by spectrometry and histology. RESULTS: Positive fluorescence was documented for every tumor seen by WD in the abdomen or right thoracic cavity. Spectrometry of lesions showed a 6.34-fold increased fluorescence intensity. Histology revealed hepatoblastoma in all specimens. CONCLUSIONS: Human hepatoblastoma can be detected by PDD in a rat model. Considering the clinical success of this method in other specialties, our findings indicate that further investigations to evaluate the benefit of PDD for children with hepatoblastoma should be performed.

Do nodal metastases from cutaneous melanoma of the head and neck follow a clinically predictable pattern?

BACKGROUND: Potential lymphatic drainage patterns from cutaneous melanomas of the head and neck are said to be variable and frequently unpredictable. The aim of this article is to correlate the anatomic distribution of pathologically involved lymph nodes with primary melanoma sites and to compare these findings with clinically predicted patterns of metastatic spread. METHODS: A prospectively documented series of 169 patients with pathologically proven metastatic melanoma was reviewed by analyzing the clinical, operative, and pathologic records. Clinically, it was predicted that melanomas of the anterior scalp, forehead, and face could metastasize to the parotid and neck levels I-III; the coronal scalp, ear, and neck to the parotid and levels I-V; the posterior scalp to occipital nodes and levels II-V; and the lower neck to levels III-V. Minimum follow up was 2 years. RESULTS: There were 141 therapeutic (97 comprehensive, 44 selective) and 28 elective lymphadenectomies (4 comprehensive dissections, 21 selective neck dissections, and 3 cases in which parotidectomy alone was performed). Overall, there were 112 parotidectomies, 44 of which were therapeutic and 68 elective. Pathologically positive nodes involved clinically predicted nodal groups in 156 of 169 cases (92.3%). The incidence of postauricular node involvement was only 1.5% (3 cases). No patient was initially seen with contralateral metastatic disease; however, 5 patients (2.9%) failed in the contralateral neck after therapeutic dissection. In 68% of patients, metastatic disease involved the nearest nodal group, and in 59% only a single node was involved. CONCLUSIONS: Cutaneous malignant melanomas of the head and neck metastasized to clinically predicted nodal groups in 92% of patients in this series. Postauricular and contralateral metastatic node involvement was uncommon.

A methodological study of the Shipley Institute of Living Scale in alcoholics and non-alcoholics: reliability, discriminating items and alternate forms.

In Study 1, 430 sober male alcoholics and 98 nonalcoholics completed the Shipley Institute of Living-Vocabulary (SILS-V) and Abstraction (SILS-A) under the standard instructions. Alcoholics performed significantly more poorly than the nonalcoholics on SILS-A. High test-retest reliability of the SILS with a 2-week interval between testings was obtained. Item analysis of the 20-item SILS-A revealed that only items 4-14 discriminated alcoholics and controls, six items required reversal of a cognitive set (reversal) and five did not (nonreversal items). Exploratory factor analyses confirmed essentially the same division of items. In Study 2, two 10-item forms of SILS-A equated for difficulty level and reversal-nonreversal cognitive demands were administered to 186 male and female college students. Results indicate the two forms are equivalent in difficulty, demonstrate no gender differences and correlate significantly with cumulative college grade point averages.

Development and application of the polymerase chain reaction for the detection and identification of Leishmania parasites in clinical material.

Detection, diagnosis and identification of Leishmaniasis may be difficult owing to low numbers of parasites present in clinical samples. The PCR has improved the sensitivity and specificity of diagnosis of several infectious diseases. A leishmania specific PCR assay was developed based on the SSUrRNA genes which amplifies DNA of all Leishmania species. Point mutations occurring within the rRNA genes allow differentiation of the Leishmania complexes using primers constructed with the 3/ ends complementary to the specific point mutations present in the SSU rRNA genes of the Leishmania species. Biopsy material, blood, lesion impressions and blood spots on filter paper can be used in the assay. In a longitudinal study on the incidence rates of VL, subclinical cases and PKDL in an endemic region of Sudan, filter paper blood spots from proven and suspected VL patients, PKDL and control samples from an endemic region in Sudan are being taken. The blood spots were analyzed in the DAT and by PCR and results compared with clinical and parasitological data. The first results indicate that the PCR on blood spots is a simple and sensitive means of detecting active VL; in PKDL patients parasites are detectable in the skin.

Does neuropsychological test performance predict resumption of drinking in posttreatment alcoholics?

The prediction of resumption of drinking in posttreatment alcoholics was investigated as a function of five possible confounding variables: depression, anxiety, childhood symptoms of attention deficit and conduct disorders and family history of alcoholism. Male and female detoxified alcoholics (n = 103) in inpatient treatment programs were administered a neuropsychological battery and retested as outpatients 14 months later; peer nonalcoholics (n = 73), given the same battery, had a similar interest interval. Alcoholics who resumed drinking (N = 41) performed significantly poorer on an overall neuropsychological performance index than abstainers (N = 62) who performed significantly poorer than nonalcoholics. Stepwise multiple regression equations using the variables noted above revealed that depressive symptoms, ADD and the performance index were the only variables to enter the prediction (R2 = .26, p less than .001); depression accounted for most of the variance. At retest all three groups improved significantly, but not differentially, and were as significantly different at retest as at initial testing. Implications of these results are discussed.

The relationship between neuropsychological and late component evoked potential measures in chronic alcoholics.

The relationships between event-related potential (ERP) measures and neuropsychological measures were investigated in a group of 39 male alcoholics and 22 age-matched male controls. Late component ERP measures such as N1, Nd, and P3 components and neuropsychological measures of perceptual-motor function, semantic and figural memory and verbal abstracting functions were included in a correlational analysis. No significant correlations between N1 amplitude or latency and neuropsychological tests were obtained. However, visual Nd amplitude correlated significantly with perceptual-motor tests and figural memory scores in the alcoholics. Significant correlations were found in alcoholics for visual P3 amplitude at PZ and delayed figural memory scores and two of the perceptual-motor tests. No significant correlations were obtained among the controls. These data indicate that significant relationships exist between some neuropsychological and ERP measures but that these relationships are restricted to measures of perceptual-motor functioning and to delayed figural memory.

Performance deficits on tests of problem solving in alcoholics: cognitive or motivational impairment?

This study tests the hypothesis that the performance deficits of alcoholics on tests of problem-solving abilities are due to impairment in motivation. The Conceptual Level Analogy Test and the Levine Hypothesis Test were administered to 40 sober middle-aged male alcoholic and 30 nonalcoholic individuals in a 2 x 2 [Group (alcoholic, nonalcoholic) by Monetary Incentive (incentive, no incentive)] between-subjects covariance design. The motivational manipulation was a performance-contingent monetary incentive. On the Levine test alcoholics performed less well than nonalcoholics but there were no incentive effects. On the analogy test, surprisingly, alcoholics did not differ from nonalcoholics in performance (probably due to the feedback necessitated by use of a performance-contingent incentive) although incentive effects were found across groups. However, there were no significant Group by Incentive interactions on either test or on self-report questionnaires of subjective states (e.g., effort expended) experienced during the tests. Thus, no evidence was found to support the impaired motivation hypothesis. The cognitive hypothesis remains as the most credible hypothesis to account for the performance deficits of alcoholics on tests of problem-solving ability.

Interpersonal problem solving in alcoholics.

In Study 1, a verbal role-playing test of interpersonal problem solving, the Adaptive Skills Battery (ASB), and selected "impersonal" neuropsychological problem-solving tests were given to male alcoholics (N = 73) in a VA alcohol treatment program and to male nonalcoholic controls (N = 36). Alcoholics' ASB competency scores under a "give your typical response" instructional set were significantly lower than controls' scores. In response to a "give the very best response" set, ASB scores for alcoholics and controls did not differ. Alcoholics' interpersonal problem-solving deficits appear to be due to their less effective execution of cognitive or problem-solving skills as opposed to their capacities for such skills. A lack of correlation between performance on impersonal neuropsychological tests and performance on the ASB suggests that these areas of functioning involve quite different psychological processes. In Study 2, alcoholics with alcoholic family members (family history positive) were found to have lower ASB scores than family history negative alcoholics. "Best" ASB responses were positively correlated with therapists' ratings of treatment behaviors and treatment outcome; "typical" ASB responses were not. Thus, alcoholics' therapeutic progress was predicted by their conceptualization of the "best" response in the interpersonal problem-solving situations and not by their typical pretreatment response.

Abstracting deficits and childhood conduct disorder as a function of familial alcoholism.

Using a large sample (n = 515), family history-positive male alcoholics (FH+) performed poorer than family history-negative (FH-) alcoholics on a test of abstracting ability. They also reported an earlier age of onset of alcoholism, more symptoms of childhood conduct disorder, and tended to report more depressive symptoms than FH- alcoholics, however, these variables were not significantly related to abstracting score. FH+ and FH- samples did not differ on average amount of ethanol consumed per day, vocabulary, state anxiety, childhood attentional deficit disorder, and childhood learning disability. The significant differences found in this study between FH+ and FH- alcoholics were minimal. With such weak effects, the inconsistent findings in studies that have investigated differences between FH+ and FH- alcoholics are understandable.

Subject selection biases in alcoholic samples: effects on cognitive performance.

The effects of subject selection bias in research on cognitive deficits in sober alcoholics were studied in a sample of 523 subjects (98 controls, 276 ineligible alcoholics, 40 eligible alcoholics who declined to participate, and 144 eligible and participatory alcoholics). All subjects received the Shipley Institute of Living Scale (Vocabulary and Abstracting subscales) and measures of anxiety, depressive symptoms, childhood hyperkinesis and attentional deficit disorders were obtained. Results indicate that current guidelines for alcoholic subject selection are biasing analyses toward support of the null hypothesis. Declined alcoholics performed more poorly on the Shipley Abstracting than did the "Used" group, yet did not differ significantly from the Used alcoholic groups on depression or anxiety. Declined alcoholics did, however, report significantly fewer Hk/MBD symptoms than did other alcoholic groups. ANCOVAs that used the affective and childhood disorders as covariates did not alter the differences in cognitive performance described above.

Learning and memory test performance in alcoholics as a function of monetary incentive.

The performance deficits of alcoholics on tests of learning and memory are typically attributed to cognitive impairment. This study tests an alternative hypothesis that the deficits are due to motivational impairment. A face-name learning and memory test was administered to 30 sober male nonalcoholic and 40 alcoholic subjects in a 2 x 2 [Group (alcoholic, nonalcoholic) x Monetary incentive (incentive, no incentive)] between-subjects design. The monetary incentive was made contingent upon performance. Alcoholics required significantly more trials to learn face-name pairs, and they recalled fewer face-name pairs at the delayed recall. Incentive subjects manifested a trend toward impairment on the trials-to-learn measure. However, there were no significant Group x Incentive interactions in learning or memory, or on a self-report questionnaire of subjective states (e.g., effort expended) experienced during the test. Thus, no evidence was found to support the impaired motivation hypothesis; the cognitive hypothesis remains as the most credible hypothesis to account for the performance deficits of alcoholics.

Learning impairment in male and female alcoholics.

Male VA alcoholics have been found to perform significantly poorer than nonalcoholics in face-name learning. Can these results be (a) replicated in a sample of male alcoholics from community treatment programs, (b) extended to female alcoholics, and (c) accounted for by childhood symptoms of attention deficit, conduct, and learning disorders? Seventy-six male and 66 female alcoholics were compared to 48 male and 49 female nonalcoholic controls on a 12-item face-name learning test. Both male and female alcoholics had poorer learning scores than their respective control groups. Learning scores were unrelated to self reports of childhood attention deficit disorder, conduct disorder, and learning problems. Whether alcoholics' impaired face-name learning is due to the direct effect of alcohol on the brain or is a concomitant of alcoholics' disrupted interpersonal relationships remains to be investigated.

Alcoholism and family history of alcoholism: effects on visual and auditory event-related potentials.

In a dual-modality paradigm, visual and auditory event-related potentials were elicited in 40 alcoholic men and 30 controls, equated with the alcoholics on age and education. Half of each group had first-degree relatives who were alcoholic (family history positive). The amplitude of the visual N1 component was reduced among the alcoholics, but their auditory N1 amplitudes were normal. Average N1 amplitudes were also smaller in the family history positive subjects but this effect was significant only for auditory stimuli. Alcoholics showed reduced average P3 amplitudes to both visual and auditory signals, particularly in the family history positive group. Clearly, stratification by family history is useful for ascertainment of ERP variation among alcoholics. There were no effects on P3 latency. Among several possible explanations of P3 deficits in alcoholics, two are particularly interesting: (1) alcoholics cannot mobilize sufficient processing resources in the service of effortful cognitive functions; (2) alcoholics, being poorly motivated, apply insufficient effort to cognitive tasks. An experiment designed to test these hypotheses is described.

Learning impairment in alcoholics using an ecologically relevant test.

Sober male middle-aged alcoholics with a mean duration of 11.5 years of abuse and abstinence for a minimum of 3 weeks performed more poorly than age- and education-equated controls on a face-name learning test, replicating previously reported findings. Duration of alcoholism was unrelated to learning scores; however, a measure of alcohol intake (maximal quantity-frequency) over the 6 months before treatment was significantly and inversely correlated with learning. Significant positive correlations between face-name learning and ratings of alcoholics' treatment behavior by their therapists provided objective evidence that the face-name learning test is ecologically relevant.

Drinking practices and neuropsychological test performance in sober male alcoholics and social drinkers.

The relationships between alcohol intake (per occasion over time) and performance on neuropsychological tests, as they might be affected by anxiety and depression, were investigated in both an alcoholic (N = 60) and social drinking (N = 43) sample. alcoholics, a Maximum Quantity Frequency (MQF) of alcohol consumed over the previous six months was found to be the best predictor of an impairment index. Neither anxiety nor depression were correlated with test performance. In social drinkers, anxiety was the best predictor of performance on the impairment index; depression was not predictive. Neither MQF nor a commonly used measure of drinking behaviors, weighted quantity per occasion (QPO), significantly predicted performance in the social drinkers once anxiety was accounted for. The results support the assumption that in alcoholics the greater and more frequent the alcohol ingestion, the more the brain's functioning is disrupted, at least as reflected in neuropsychological test performance. Anxiety appears to play a major role in the test performance of social drinkers and should be monitored in future studies in this research area.

Neuropsychological differences between male familial and nonfamilial alcoholics and nonalcoholics.

The hypothesis was tested that neuropsychological differences exist between males who have an alcoholic parent, sister, or brother (FH+) versus those who do not (FH-). Neuropsychological tests measuring verbal, learning/memory, abstracting/problem solving, and perceptual-motor performance were given to four groups of middle-aged subjects: alcoholic FH+ (n = 41); alcoholic FH- (n = 27); nonalcoholic FH+ (n = 19); and nonalcoholic FH- (n = 43). FH+ subjects performed significantly poorer than FH- subjects on the abstracting/problem solving and perceptual-motor tasks, and approached significance on the verbal and learning/memory measures. Alcoholics performed more poorly than nonalcoholics on abstracting/problem solving and learning/memory tasks. There were no groups by family history significant interactions. From these results we suggest: a performance deficit in abstracting/problem solving and possibly learning/memory may antedate the alcoholic stage in FH+ individuals; alcoholism and positive family history of alcoholism have independent, additive deleterious effects on cognitive-perceptual functioning; and future neuropsychological studies of alcoholism should consider the frequency of FH+ and FH- individuals in both alcoholic and control groups.

The distribution of copper in sickling erythrocytes as determined by an IBM cell separator.

Elevated levels of copper have been found in sickling erythrocytes. Since this copper may inhibit sickling or induce hemolysis the authors decided to investigate the distribution of copper in sickling erythrocytes to gain some insight into its origin. When samples of sickling erythrocytes were fractionated by density gradient centrifugation with an IBM cell separator and the fractions analyzed for copper, it was found that the copper to hemoglobin ratio of the different fractions varied several fold. This finding indicated that the copper in sickling erythrocytes did not equilibrate with the copper in serum or other cells and that the copper was present in the cells when they were released into the blood stream. When erythrocytes were obtained from a sickle cell patient four days post-crises, a large amount of residual copper could be observed in the first (youngest) fraction. It was suspected that this copper was in mitochondrial residues. It was also observed that copper levels tended to be higher in control and sicklings erythrocytes during the winter months. The predominance of the first fraction in samples of sickling erythrocytes taken during the winter months suggests that the turnover of sickling erythrocytes is accelerated at this time.

Physiological stresses related to hypercapnia during patrols on submarines.

Physiological studies on hypercapnic effects carried out on 13 Polaris patrols are summarized. The average CO2 concentrations ranged from 0.7-1% CO2; CO2 was identified as the only environmental contaminant of the submarine atmosphere that has a direct effect on respiration in the concentration range found in the submarine atmosphere. A comparison has been made of physiological effects produced during 42 days of exposure to 1.5% CO2 during laboratory studies (L.S.) with those observed during 50 to 60 days of exposure to 0.7-1% CO2 on patrols (P.S.). A close similarity was found in the effects on respiration and blood electrolytes under both conditions. Respiratory minute volume was elevated by 50-63% because of increased tidal volume. The physiological dead space increased 60%. Vital capacity showed a trend toward a decrease. Studies of acid-base balance carried out during patrols demonstrated cyclic changes in blood pH and bicarbonate; pH and blood bicarbonate fell during the first 17 days of exposure, rose during the subsequent 20 days, and decreased again after 40 days. These cycles cannot be explained on the basis of known renal regulations in CO2-induced acidosis and were not found during exposure to 1.5% CO2. The hypothesis is advanced that these changes in acid-base balance are caused by cycles in CO2 uptake and release in bones. The time constants of the bond CO2 stores fit the observed length of cycles in acid-base balance. Correlation with cycles of calcium metabolism provides further support for this hypothesis. Red cell electrolytes showed similar changes under 1.5% CO2 (L.S.) and 0.7-1% CO2 (P.S.). Red cell sodium increased and potassium decreased. Moreover, red cell calcium also increased under both conditions. The significance of these red cell electrolyte changes in regard to changes in permeability and active transport remains to be clarified. An increased gastric acidity was found during patrol (exposure to 0.8-0.95% CO2). The changes observed during patrols disappeared during the recovery periods.