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Biomedical subjects

C Rosenberg

Publications and source records attributed to C Rosenberg.

At least 19 recordsLinked to original sources

Signaling and host range variation in nodulation.

Rhizobium, Bradyrhizobium, and Azorhizobium strains, collectively referred to as rhizobia, elicit on their leguminous hosts, in a specific manner, the formation of nodules in which they fix nitrogen. Rhizobial nod genes, which determine host specificity, infection, and nodulation, are involved in the exchange of low molecular weight signal molecules between the plant and the bacteria as follows. Transcription of the nod operons is under the control of NodD regulatory proteins, which are specifically activated by plant flavonoid signals. The common and species-specific structural nod genes are involved in turn in the synthesis of specific lipo-oligosaccharides that signal back to the plant to elicit root-hair deformations, cortical-cell divisions, and nodule-meristem formation.

Fabaceae

PRAD1 (cyclin D1): a parathyroid neoplasia gene on 11q13.

Hyperparathyroidism is a central component of multiple endocrine neoplasia type 1 (MEN 1), and both sporadic and familial forms of parathyroid disease may share certain pathogenetic features. We recently identified a gene that is clonally rearranged with the PTH locus in a subset of sporadic parathyroid adenomas. This candidate oncogene, PRAD1 (previously D11S287), appears to contribute to parathyroid tumorigenesis in a fashion analogous to activation of C-MYC or BCL-2 by rearrangement with tissue-specific enhancers of the immunoglobulin genes in B-lymphoid neoplasia. The PRAD1 gene maps to 11q13 and has been linked to the BCL-1 breakpoint locus, although not to the most tightly linked MEN 1 markers, by pulsed field gel electrophoresis. PRAD1 may, in fact, be the long-sought BCL-1 lymphoma oncogene. PRAD1 encodes a novel type of cyclin protein and thus may normally function in controlling the cell cycle, perhaps through direct interaction with cdc2 or a related kinase. PRAD1's possible primary, or more likely secondary, involvement in the pathogenesis of MEN 1-related tumors is unknown and under investigation.

Amino Acid Sequence

Analysis of reciprocal translocations by chromosome painting: applications and limitations of the technique.

Fluorescent in situ hybridization with chromosome-specific DNA libraries (chromosome painting) is an important new method for assessing chromosome rearrangements. In the research presented in this paper, two familial reciprocal translocations have been studied in the balanced and unbalanced forms, using both traditional G-banding techniques and chromosome painting. Although for each case two chromosomes were involved in the rearrangement, we found that only one chromosome library was suitable for detecting the translocation. These findings illustrate both the potential and the limitations of chromosome painting as a diagnostic tool in cytogenetics.

Adult

Impact of do-not-resuscitate legislation on the use of cardiopulmonary resuscitation in three teaching hospitals.

Under New York State's unique do-not-resuscitate law, patients admitted to a hospital are assumed to consent to cardiopulmonary resuscitation unless a do-not-resuscitate order has been written in accordance with specific stipulations. This study was undertaken to determine if the law would significantly change the use of cardiopulmonary resuscitation. The charts of 952 patients who died on the medical services of Bellevue, New York University, and New York Veterans hospitals during the 12-month periods before and after the law went into effect were reviewed. The proportion of patients undergoing cardiopulmonary resuscitation was determined. To take into account the effects of potential confounders (ie, hospital, sex, race or ethnic group, age, diagnosis), a multiple logistic regression analysis was performed. The relative risk for cardiopulmonary resuscitation was found to be 0.81, (95% confidence interval: 0.59-1.10) after the law as compared with before, which was not statistically significant. Although patients with chronic or potentially reversible illness were much more likely than those with hopeless illness to undergo cardiopulmonary resuscitation (relative risk of 7.08 [3.23-15.54] and 12.89 [8.71-19.07], respectively), the data failed to show that the law had an impact on the use of cardiopulmonary resuscitation in any of the disease categories. Total use of formal do-not-resuscitate orders increased from 32.7% to 83.9% (p less than .0001), although at Bellevue, where documentation was high before the law, no further increase occurred.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult

Origin of chromosome rearrangements in two long-lived human keratinocyte lines.

We have determined the origin of the extra chromosomal material in the karyotypes of two spontaneously-occurring long-lived human keratinocyte lines, HKC-N2 and HKC-N6. In each case the extra material was derived from the chromosome on which it was located. Possible relationships between the triplication of chromosomal material and the overcoming of cell senescence are discussed.

Cell Line

Endogenous hormones and breast cancer: a prospective cohort study.

A cohort study is under way in New York City to evaluate how levels of endogenous reproductive hormones influence the risk of breast cancer. The study, in which approximately 15,000 women are being recruited, utilizes a prospective design in which volunteers are asked to provide repeated specimens of serum during the period 1985-1992. A case-control study nested within the cohort is planned by which specimens from all cases arising in the population and from a randomly selected sample of time-matched controls will be analyzed and compared. As of December 31, 1989, 13,609 volunteers had donated blood specimens, about 50% of whom had already donated more than once. Of the 187 incident breast cancer cases who are expected to arise in the cohort before the end of 1992, 77 have been detected thus far.

Adult

Genetic analysis of a region of the Rhizobium meliloti pSym plasmid specifying catabolism of trigonelline, a secondary metabolite present in legumes.

Genes controlling the catabolism of trigonelline, a secondary metabolite that is often present in legumes, are located on the pSym megaplasmid of Rhizobium meliloti. To investigate the role of bacterial trigonelline catabolism in the Rhizobium-legume symbiosis, we identified and characterized the R. meliloti RCR2011 genetic loci (trc) controlling trigonelline catabolism. Tn5-B20 mutagenesis showed that the trc region is a continuous DNA segment of 9 kb located 4 kb downstream of the nifAB and fdxN genes. Trc mutants fell into two classes according to their phenotype and location: (i) mutants carrying Tn5-B20 insertions in the right-hand part of the trc region were incapable of growing on trigonelline as the sole carbon and/or nitrogen source, and (ii) insertions in the left-hand part of the trc region resulted in delayed growth on trigonelline as the sole carbon and/or nitrogen source. No significant defect in nodule formation or nitrogen fixation was detected for mutants of either class. Screening of a set of R. meliloti strains from various geographical origins showed that all of these strains are able to catabolize trigonelline and show sequence homology between their megaplasmids and a trc probe.

Alkaloids

[Anatomo-morphologic aspects of the jaws as indications for osseointegrated implants in the partially edentulous].

Considering the great apogee reached in the last few years by the osseointegrated implants used in modern odontology it makes necessary to go deeper into the analysis of some anatomo-morphologic mandible aspects on partial edentates. Actually, these make the major percentage of patients who ask or are in effect candidates to rehabilitation by means of this technic. So it is described on individual analysis for each clinical case classified according to Kennedy's classification, giving emphasis to determination and real evaluation of height, thickness and form of partial edentates' mandibles. Furthermore, there are given some prosthetic models to be considered in the osseointegrated implant indications on partial edentates.

Alveolar Bone Loss

Fragile X frequency in a mentally retarded population in Brazil.

Seventy-five male and 50 female students from 2 special schools for mildly, moderately retarded, or borderline individuals were screened clinically and cytogenetically in order to estimate the contribution of fragile X [fra(X)] syndrome to the cause of mental retardation in Brazil. We found 6 males (8%) from 4 families and 2 unrelated females (4%) with fra(X) chromosomes. One male and one female were isolated cases. The estimated frequency of Martin-Bell [fra(X)] syndrome among mentally impaired individuals in Brazil was similar to that previously reported in other countries.

Adolescent

Endometrial laser ablation in rabbits: a comparative study of three laser types.

Endometrial laser ablation is one of the alternatives to hysterectomy in cases of intractable uterine bleeding. It is currently performed using the Nd:YAG laser at 1.06 microns. The aim of this study was to compare the tissue effect of three types of laser irradiation (Nd:YAG laser at 1.06 and 1.32 microns and holmium laser at 2.12 microns) on the rabbit endometrium. Crater formation, coagulation necrosis, and muscle necrosis were evaluated at the time of ablation, as well as at 1 week and 4 weeks postablation. The results were assessed by determining the depth and width of the affected portion in the uterine wall (lumen to serosa). It was shown that Nd:YAG laser at 1.32 microns caused more generalized and extended effects as compared with the other laser types examined. Endometrial regeneration was faster after ablation by the Nd:YAG laser at 1.06 microns and the holmium laser than by the Nd:YAG laser at 1.32 microns. The widest range of "ablation energy" (defined as that causing ablation without muscle damage) was achieved by applying the holmium laser. Further evaluation of the holmium laser for this indication is recommended.

Animals

Latex agglutination for the rapid diagnosis of streptococcal pharyngitis: use by house staff in a pediatric emergency service.

A rapid latex agglutination (LA) method was evaluated in 2401 consecutive pediatric patients presenting to an emergency service with suspected group A beta-hemolytic streptococcal pharyngitis. LA tests were performed by the treating physicians, who were not blinded to the clinical condition of the children and who made therapeutic decisions based on the results of the tests. When compared with anaerobic culture, the LA method had a sensitivity of 91%, a specificity of 82%, and a positive predictive value of 43%. There was a marked seasonal variation in the positive predictive value: 62% in winter and 16% in summer. However, even in peak streptococcal pharyngitis season (January to March), basing therapy on a positive LA test leads to the unnecessary treatment of a large number of patients. Therefore, we cannot recommend the routine performance of this test by all practitioners in all clinical settings.

Child

A family study of sleep apnea. Anatomic and physiologic interactions.

The distribution of symptoms, physiologic responses, and upper airway structure in members of one family with three generations of subjects with sleep apnea (SA) is reported. Questionnaire data were obtained from ten family members (ages 7 to 66 years), overnight sleep studies were performed in nine subjects, and ventilatory responses to hyperoxic hypercapnia and to eucapnic hypoxia and cephalometry were obtained in five subjects. All ten family members reported habitual snoring or nighttime snorting/gasping; five of ten family members also reported excessive daytime sleepiness. All studied subjects except for a pregnant woman had greater than ten apneas/hypopneas per hour. Ventilatory responses to hypoxia were markedly reduced in all five subjects studied (less than or equal to 0.51 L/min/SaO2); hypercapnic responses were reduced in three of five subjects (less than or equal to 0.61 L/min/mm Hg CO2). No subject was morbidly obese (body mass index less than 29 kg/m2) or demonstrated retrognathia. The posterior airway space was reduced in three subjects, and the mandibular to hyoid distance was increased in four subjects. The two subjects with the longest soft palates and the most inferiorly displaced hyoids had the most severe sleep disorder. Sleep apnea was present, albeit less profound, in the one subject with normal anatomy who had an abnormal hypoxic ventilatory response. The distribution of these physiologic and anatomic measurements in this family provides further support for a genetic basis for SA, and suggests that the disorder may occur as a result of interactions between ventilatory control abnormalities and anatomic risk factors.

Adult

Tissue effects of a new laparoscopic carbon dioxide laser probe.

The effects of CO2 laser beam delivered through a new laparoscopic probe on rabbit uteri is presented. This device has an outer diameter of 4.9 mm and can be delivered through most of the standard operative laparoscopic accessories. Two probes with miniature zinc selenide lenses of 6.5 mm and 17 mm back focal length attached at the distal end were tested. Through each probe, constant 0.5-second pulses and power levels of 5, 10, and 15 W were applied in three different lens-to-target distances. Measurements of beam spot diameters and microscopic crater characteristics revealed significant differences as a result of minor shifting of lens-target distance. From 7 to 9 mm beyond the focal plane and at power levels of 5 to 10 W, negligible tissue effects could be detected. This was defined as an "optical back-stop" effect. A new application mode using an easily maneuverable probe for cutting and coagulating [focusing/defocusing] effects increases the options available for operative laparoscopy.

Animals

Distribution of 3H-morphine following lumbar subarachnoid injection in unanesthetized rabbits.

Morphine sulfate (40-100 micrograms) and 3H-morphine (125-200 pmol) were injected into the lumbar subarachnoid space of 18 unanesthetized rabbits through a surgically implanted catheter. Radioactivity remaining in the spinal cord 2, 4, 6, and 12 h later revealed recovery (mean +/- SEM) of 45 +/- 5.6% (n = 3), 30.5 +/- 14.1% (n = 4), 11.23 +/- 4.4% (n = 3), and 3.7 +/- 1.1% (n = 3), respectively, of the injected radioactivity. Tritiated morphine was found to be predominantly centered around the injection site, with limited rostral and caudal spread in the cord. No significant radioactivity was detected in plasma or cerebrospinal fluid (CSF) samples from the cisterna magna taken at 5, 15, 30, min and 1, 2, 4, 6, 12, and 24 h after receiving radioactive labeled drug (with the exception of that in one rabbit). Of the injected radioactivity, 75% was recovered in the urine in 12 h. These results suggest that the persistence of morphine in the spinal cord could account for its prolonged analgesic effect following intrathecal administration.

Animals

The Rhizobium meliloti host range nodQ gene encodes a protein which shares homology with translation elongation and initiation factors.

The Rhizobium meliloti nod region IIb is involved in host-range determination: (i) the presence of region IIb is necessary for transfer of alfalfa root hair curling ability to Rhizobium leguminosarum biovar trifolii; (ii) a mutation in region IIb extends the R. meliloti infection host range to Vicia sativa nigra; (iii) dominance of R. meliloti nod genes over R. leguminosarum biovar viciae nod genes is abolished by mutations in region IIb. The nucleotide sequence of this region has been determined. Genes corresponding to the two open reading frames identified are designated nodP and nodQ. The predicted amino acid sequence of the NodQ protein shows homology with translation initiation and elongation factors. The consensus sequence involved in the GTP-binding domain is conserved.

Amino Acid Sequence