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Biomedical subjects

H Rosenberg

Publications and source records attributed to H Rosenberg.

At least 19 recordsLinked to original sources
PubMed2005

Influence of the kidney histology at the time of donation on long term kidney function in living kidney donors.

Living donation is the best choice for kidney transplantation, obtaining long-lasting good results for the recipient. Some concern still remains regarding the donor's long-term health. Kidney biopsy was routinely performed in our donor population at the time of donation many years ago. We found the existence of morphological kidney disease in those samples, in spite of normal clinical evaluations before donation. We attempted to correlate those abnormalities with long-term clinical outcomes. Donors were at least 10 years after surgery. A medical interview, including the SF-36 Health Survey, laboratory evaluation, and ambulatory blood pressure monitoring was performed on 27 donors meeting the inclusion criteria. Two donors had died after donation from unrelated causes with no known nephropathy. Histological analysis showed abnormalities in 16 of 29 donors. We found an increased prevalence of hypertension compared to the general population. Interestingly, there was no proteinuria in the donor population, and none developed clinical nephropathy. All subjects felt emotionally rewarded with donation, stating that their lives had no limitations. Our results suggest that kidney biopsy is neither necessary nor useful prior to donation because, although many donors had morphological kidney disease, none developed clinical nephropathy in the long term.

Blood Pressure Monitoring, Ambulatory↗
PubMed2001

Identification and functional characterization of a novel ryanodine receptor mutation causing malignant hyperthermia in North American and South American families.

Malignant hyperthermia is a pharmacogenetic disorder associated with mutations in Ca(2+) regulatory proteins. It manifests as a hypermetabolic crisis triggered by commonly used anesthetics. Malignant hyperthermia susceptibility is a dominantly inherited predisposition to malignant hyperthermia that can be diagnosed by using caffeine/halothane contracture tests. In a multigenerational North American family with a severe form of malignant hyperthermia that has caused four deaths, a novel RYR1 A2350T missense mutation was identified in all individuals testing positive for malignant hyperthermia susceptibility. The same A2350T mutation was identified in an Argentinean family with two known fatal MH reactions. Functional analysis in HEK-293 cells revealed an altered Ca(2+) dependence and increased caffeine sensitivity of the expressed mutant protein thus confirming the pathogenic potential of the RYR1 A2350T mutation.

Amino Acid Substitution↗
PubMed2001

Identification of the Arg1086His mutation in the alpha subunit of the voltage-dependent calcium channel (CACNA1S) in a North American family with malignant hyperthermia.

Individuals from a large North American population were screened for the presence of the mutation in the alpha1 subunit of the voltage-dependent calcium channel (CACNA1S) that has recently been associated with malignant hyperthermia (MH). This Arg1086His mutation was screened for in 154 MH normal (MHN) individuals and 112 MH susceptible (MHS) individuals, who were diagnosed by the North American protocol of the in vitro contracture test. PCR and restriction enzyme analysis was used to test for the mutation. The Arg1086His mutation in the CACNA1S was not found in any of the MHN individuals. In contrast, two related individuals (grandfather and grandson, father and son of the MH proband) among the MHS group exhibited this mutation. However, a third MHS individual in the same family (granddaughter, cousin of the grandson) did not exhibit this mutation. These results indicate that this mutation may be associated with MH in this family. Genetic alterations in the CACNA1S associated with MH are present in approximately 1% of this North American MHS population.

Animals↗
PubMed2001

North American malignant hyperthermia population: screening of the ryanodine receptor gene and identification of novel mutations.

BACKGROUND: Malignant hyperthermia (MH) is a disorder of skeletal muscle manifested as a life-threatening hypermetabolic crisis in susceptible individuals after exposure to inhalational anesthetics and depolarizing muscle relaxants. Mutations in the gene encoding the skeletal muscle ryanodine receptor (RYR1) are considered a common cause of the disorder, and, to date, more than 20 RYR1 mutations have been reported in European and Canadian families. Some studies suggest that differences may exist in the frequencies and distribution of mutations in the RYR1 gene between European and North American MH families the frequency and distribution of mutations in the RYR1 gene. METHODS: Skeletal muscle samples from 73 unrelated individuals diagnosed as MH susceptible according to the North American MH caffeine-halothane contracture test were studied. Genomic DNA of MH-susceptible patients was investigated by polymerase chain reaction-based restriction fragment length polymorphism, single-strand conformation polymorphism, and sequencing analysis. The majority of known RYR1 mutations were analyzed using the restriction fragment length polymorphism method, whereas new mutations were searched by single-strand conformation polymorphism in exons 12, 15, 39, 40, 44, 45, and 46 of the gene. RESULTS: Seven known RYR1 mutations (Arg163Cys, Gly248Arg, Arg614Cys, Val2168Met, Thr2206Met, Gly2434Arg, and Arg2454His) were detected at frequencies of 2.7, 1.4, 1.4, 1.4, 1.4, 5.5, and 4.1%, respectively. In addition, three novel amino acid substitutions (Val2214Ile, Ala2367Thr, and Asp2431Asn) were detected at frequency of 1.4% each. These 10 mutations account for 21.9% of the North American MH-susceptible population. CONCLUSION: Three novel candidate mutations in the RYR1 gene were identified in these MH patients. The frequency and distribution of RYR1 mutations observed in this North American MH population was markedly different from that previously identified in Europe. Larger-scale studies are necessary to clarify the type and frequency of mutations in RYR1 associated with MH in North American families.

Genetic Linkage↗
PubMed2001

[Metachronous pancreatic metastasis of a renal cell carcinoma. 3 new cases].

We report two males and one female, aged 71, 81 and 73 years old respectively, previously operated of a renal cell carcinoma. During the follow up of the 71 years old male, the CAT scan showed three lesions in the pancreas. Also, the CAT scan in the female showed one lesion in the tail of the pancreas. The 81 years old male was admitted to the emergency room due to a upper gastrointestinal bleeding. Endoscopy showed a proliferating lesion in the second portion of the duodenum whose biopsy showed a clear cell carcinoma. The CAT scan showed also a tumoral mass in the head of the pancreas. All three patients were subjected to surgical resection of the tumors without postoperative complications or mortality.

Aged↗
PubMed2000

Assessment of university students' coping strategies and reasons for driving in high-risk drinking-driving situations.

A total of 116 students (87 women; 29 men) enrolled at a large, public Midwestern university in the United States were recruited to complete a set of demographic questionnaires and drinking-driving episode surveys. The latter surveys assessed participants' reported motivations for driving or not driving during four recent drinking episodes. Content analyses were used to develop lists of commonly reported reasons for not driving (e.g. found alternate transportation), reasons for driving after drinking (e.g. perceived need to go to destination), potential alternatives to driving after drinking (e.g. walking to destination), and strategies used to avoid detection or arrest by police (e.g. driving more slowly, using back roads or side streets). Participants made both situational and self-coping attributions to explain why they did not, on occasion, drive after drinking. These results may be used as a foundation for prevention and education programs that are designed to: (a) encourage use of coping strategies and alternatives to driving while disputing peer-generated justifications for driving after drinking, and (b) challenge the value of potentially unsafe strategies for avoiding detection and arrest when driving under the influence.

Accidents, Traffic↗
PubMed2000

Assessing and training recognition of intoxication by university students.

Forty-five undergraduate volunteers attended either a 2-session recognition of intoxication training program or a 2-session attention-placebo control group. Stimulus videotapes portrayed male and female university students (targets) performing various tasks both before drinking and again after consumption of 3 to 5 standard drinks. Participants' accuracy in recognizing whether videotaped targets had or had not been drinking (target status) was assessed 1 week posttraining and 2 months posttraining. At the 1-week follow-up assessment, participants in the training program had a higher mean number of accurate ratings of target status compared with the attention-placebo control group. In addition, a larger proportion of training-group participants expressed an overall preference to rate a target as not having been drinking if they were unsure of target status. These effects were not maintained at the 2-month follow-up assessment.

Adult↗
PubMed2000

Attenuated nontoxinogenic and nonencapsulated recombinant Bacillus anthracis spore vaccines protect against anthrax.

Several highly attenuated spore-forming nontoxinogenic and nonencapsulated Bacillus anthracis vaccines differing in levels of expression of recombinant protective antigen (rPA) were constructed. Biochemical analyses (including electrospray mass spectroscopy and N terminus amino acid sequencing) as well as biological and immunological tests demonstrated that the rPA retains the characteristics of native PA. A single immunization of guinea pigs with 5 x 10(7) spores of one of these recombinant strains, MASC-10, expressing high levels of rPA (>/=100 microgram/ml) from a constitutive heterologous promoter induced high titers of neutralizing anti-PA antibodies. This immune response was long lasting (at least 12 months) and provided protection against a lethal challenge of virulent (Vollum) anthrax spores. The recombinant B. anthracis spore vaccine appears to be more efficacious than the vegetative cell vaccine. Furthermore, while results clearly suggest a direct correlation between the level of expression of PA and the potency of the vaccine, they also suggest that some B. anthracis spore-associated antigen(s) may contribute in a significant manner to protective immunity.

Animals↗
PubMed2000

Understanding the relation between expectancies and drinking among DUI offenders using expectancy categories.

OBJECTIVE: In the context of several recent studies that have found negative expectancies to predict drinking-related variables, the present study was designed to examine the relationships among positive expectancies, negative expectancies and drinking, in a sample of DUI offenders. METHOD: Participants (N = 96; 75% male) recruited from a 3-day residential alcohol education program completed a demographic data sheet, the Negative Alcohol Expectancy Questionnaire (NAEQ), the Alcohol Expectancy Questionnaire (AEQ) and the Customary Drinking Record upon admission to treatment. At a 3-month follow-up assessment, these measures were re-administered to 49% of the sample. RESULTS: Hierarchical multiple regression revealed that both positive and negative expectancies were related to number of drinks in the previous 30 days. Stepwise multiple regression revealed that baseline drinking and negative expectancies were both related to number of drinking days at the 3-month follow-up assessment. To assess the interplay of positive and negative expectancies as they relate to drinking, participants were categorized as "low" or "high" on both the AEQ and the NAEQ. The low positive/low negative group drank more than the low positive/high negative group. There was no statistically significant difference in drinking between the high positive/low negative and the high positive/high negative group. CONCLUSIONS: This study provides additional evidence that negative alcohol expectancies are related to drinking. These findings suggest that the proposed restraining influence of negative expectancies on drinking may be reduced when a drinker has concurrent positive expectancies which are high.

Adolescent↗
PubMed2000

Influence of dose and beverage type instructions on alcohol outcome expectancies of DUI offenders.

OBJECTIVE: To test the hypothesis that self-reported alcohol outcome expectancies are situationally specific beliefs that vary depending on contextual variables, such as the quantity and type of beverage one is instructed to imagine consuming. METHOD: One hundred thirty DUI offenders attending a 72-hour weekend program were randomly assigned to either a "small dose" or "large dose" instruction condition and then completed five versions of the Comprehensive Effects of Alcohol scale, a separate version for each of five beverage types ("alcohol," "beer," "wine," "mixed drinks" and "straight liquor"). RESULTS: Two separate 2 (dose) x 5 (beverage type) ANOVAs revealed that positive and negative expectancies varied significantly as a function of both dose and beverage type. Specifically, participants endorsed more positive outcomes and more negative outcomes when they imagined drinking a large amount versus a small amount. In addition, participants endorsed significantly more positive expectancies for beer and mixed drinks than for wine. They endorsed the largest number of negative expectancies for straight liquor and the fewest for wine. CONCLUSIONS: Expectancies are to some degree context-bound and researchers and clinicians should consider providing explicit dose and beverage type instructions to research participants and clients when they use self-report questionnaires to assess alcohol outcome expectancies.

Adult↗
PubMed2000

[Apoplexy in pituitary metastasis of renal cell carcinoma. Clinical case followed for 7 years].

We report a man in whom a 15 cm. renal tumor was excised at the age of 49. The pathological examination showed a clear cell carcinoma. Five years later, he presented with headache, vomiting and unilateral palpebral ptosis. Imaging studies showed a sellar tumor with pituitary apoplexy. The tumor was excised and the pathological study disclosed a clear cell tumor, positive for vimentin, cytokeratins AE1 and AE3 and immunohistochemically negative for LH, TSH, ACTH and GH. Considering the similar histopathological features, it was considered as a metastasis of the renal tumor. The patient was supplemented with thyroid, adrenal and gonadal hormones. Seven years later, he presented a new tumor in the remaining kidney, that corresponded to a cystic papillary renal cell carcinoma. Afterwards, he presented a transitional urinary bladder tumor. Mortality associated to renal cell tumors is 90% at 5 years, and pituitary metastases are extraordinarily uncommon.

Adenocarcinoma, Clear Cell↗
PubMed1999

Simple intratesticular cysts in children: preoperative sonographic diagnosis and histological correlation.

BACKGROUND: Simple intratesticular cysts are rare in children and have been considered the most uncommon cause of scrotal cystic masses in this age group. The exact etiology of these lesions is still unclear. High-resolution ultrasonography has been proved to be a reliable and accurate imaging modality in the evaluation of scrotal abnormalities in children. PATIENTS AND METHODS: We report the sonographic findings in five boys aged from 4 to 10 months who presented with a scrotal mass and had a simple intratesticular cyst. Ultrasonography showed that all of them displayed a characteristic appearance and provided the necessary information to perform conservative surgery, with testicular preservation in four infants. In one infant, the cyst involved most of the testis, and an orchiectomy was performed. RESULTS: Pathological examination revealed a single smooth-walled cystic structure, with clear and serous fluid, lined with flattened epithelial cells in all of the infants. CONCLUSION: Our findings appear to support the hypothesis that these cysts could correspond to mesothelial inclusions. Sonographically, differential diagnosis should include mainly epidermoid cysts of the testis, which are mostly cystic but characteristically contain some echoes within them, in contrast to simple cysts and cysts of the tunica albuginea, which lie outside the testicular parenchyma.

Cysts↗
PubMed1999

Comparison of European and North American malignant hyperthermia diagnostic protocol outcomes for use in genetic studies.

BACKGROUND: Halothane and caffeine diagnostic protocols and an experimental ryanodine test from the North American Malignant Hyperthermia (MH) Group (NAMHG) and the European MH Group (EMHG) have not been compared in the same persons until now. METHODS: The outcomes of the NAMHG and EMHG halothane and caffeine contracture tests were compared in 84 persons referred for diagnostic testing. In addition, the authors assessed the experimental ryanodine protocol in 50 of these persons. RESULTS: Although the NAMHG and EMHG halothane protocols are slightly different methodologically, each yielded outcomes in close (84-100%) agreement with diagnoses made by the other protocol. Excluding 23 persons judged to be equivocal (marginally positive responders) by the EMHG protocol resulted in fewer persons classified as normal and MH susceptible (42 and 19, respectively) than those classified by the NAMHG protocol (48 and 34, respectively). For the 61 persons not excluded as equivocal, the diagnoses were identical by both protocols, with the exception of one person who was diagnosed as MH susceptible by the NAMHG protocol and as "normal" by the EMHG protocol. The NAMHG protocol produced only two equivocal diagnoses. Therefore, a normal or MH diagnosis by the NAMHG protocol was frequently associated with an equivocal diagnosis by the EMHG protocol. The time to 0.2-g contracture after the addition of 1 microM ryanodine completely separated populations, which was in agreement with the EMHG protocol and, except for one person, with the NAMHG protocol. CONCLUSIONS: Overall, the NAMHG and EMHG protocols and the experimental ryanodine test yielded similar diagnoses. The EMHG protocol reduced the number of marginal responders in the final analysis, which may make the remaining diagnoses slightly more accurate for use in genetic studies.

Caffeine↗
PubMed1999

ATX II, a sodium channel toxin, sensitizes skeletal muscle to halothane, caffeine, and ryanodine.

BACKGROUND: The function or expression of subtypes of the sodium ion (Na+) channel is altered in biopsies or cultures of skeletal muscle from many persons who are susceptible to malignant hyperthermia (MH). ATX II, a specific Na+ channel toxin from a sea anemone, causes delayed inactivation of the channel similar to that seen in cell cultures of MH muscle. ATX II was added to skeletal muscle to determine whether altered Na+ channel function could increase the sensitivity of normal skeletal muscle to agents (halothane, caffeine, ryanodine) to which MH muscle is hypersensitive. METHODS: Studies were performed of fiber bundles from the vastus lateralis muscle of persons who were deemed not MH susceptible (MH-) or MH susceptible (MH+) according to the MH diagnostic test and of strips of diaphragm muscle from rats. Preparations in a tissue bath containing Krebs solution were connected to a force transducer. ATX II was introduced 5 min before halothane, caffeine, or ryanodine. RESULTS: ATX II increased the magnitude of contracture to halothane in preparations from most MH-, but not MH+, human participants. After ATX II treatment, preparations from 9 of 24 MH- participants generated contractures to halothane, 3%, that were of the same magnitude as those from MH+ participants. Preparations from four of six ATX II-treated healthy participants also gave responses of the same magnitude as those of MH-susceptible participants to a graded halothane challenge (0.5-3%). The contractures to bolus doses of halothane in specimens from male participants were more than three times larger than the contractures in specimens from female participants. In rat muscle, ATX II increased the magnitude of contracture to caffeine (2 mM) and decreased the time to produce a 1-g contracture to ryanodine (1 microM). CONCLUSIONS: ATX II, which causes delayed inactivation of the Na+ channel in cell cultures similar to that reported in cultures of MH+ skeletal muscle, increased the sensitivity of normal muscle to three agents to which MH+ muscle is hypersensitive. The increased sensitivity to halothane, 3%, occurred in most (79%), but not all, MH- participants, and this effect was most evident in male participants. Therefore, abnormal function of the Na+ channel, even if it is a secondary event in MH, may contribute to a positive contracture test result for MH.

Animals↗