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Biomedical subjects

R Rubinstein

Publications and source records attributed to R Rubinstein.

At least 37 records · Page 2Linked to original sources
PubMed1996

Use of 201Thallium brain SPECT, image registration, and semi-quantitative analysis in the follow-up of brain tumors.

OBJECTIVE: To assess the use of 201Thallium SPECT and of Thallium (Tl) uptake indices in the detection and follow-up of cerebral tumors. MATERIAL AND METHODS: Two-hundred eighty 201Tl, 135 99mTc-HMPAO scintigraphies and 280 MRI studies were acquired in 135 patients with cerebral tumors. Three types of Tl uptake indices were calculated by establishing the ratio of the lesion activity to an homologous ROI (I1), the contralateral hemisphere (I2), and the contralateral scalp (I3). Intermodal coregistration between Tl-SPECT and MRI when used, was performed using Pietrzyk visual interactive method. RESULTS: Tl uptake indices showed mean values of 2.0 +/- 0.5 (I1); 1.77 +/- 0.57 (I2) and 1.11 +/- 0.40 (I3) in positive scans, and of 1.05 +/- 0.22 (I1), 0.88 +/- 0.22 (I2) and 0.50 +/- 0.15 (I3) in negative scans, respectively. A linear combination of the two less correlated indices lead to a more powerful discrimination between positive and negative studies. Longitudinal follow-up studies in the same patients showed good concordance between the index values and the course of the disease. CONCLUSION: The use of Tl uptake indices improves the accuracy of Tl-SPECT in the follow-up of brain tumors.

Adolescent↗
PubMed1995

Malignant syphilis (lues maligna) and concurrent infection with HIV.

BACKGROUND: During the past 2 1/2 years we observed six patients who had a reactive serology for syphilis, of which four developed widespread noduloulcerative and two vesiculonecrotic lesions. The purpose was to report the occurrence of lues maligna, a rare form of secondary syphilis, in five patients infected with the human immunodeficiency virus (HIV) and in one patient with risk factors for infection. METHODS: Tzanck preparations, viral cultures, and skin biopsies were performed to evaluate the etiology of the lesions. RESULTS: Syphilis serology titers ranged from 1:32 to 1:128 and in one instance was as low as 1:8. Such titers can also be found in patients with the latent form of syphilis. Therefore, confirmation of the clinical diagnosis of lues maligna was dependent on skin biopsies that were compatible with secondary syphilis and negative viral studies that excluded varicella, disseminated varicella-zoster or herpes simplex. Lues maligna takes an aggressive course in HIV-infected patients since four of the patients required hospitalization and the two patients who refused to complete treatment, subsequently developed more severe skin and constitutional symptoms. CONCLUSIONS: HIV-infected patients are at risk for developing lues maligna. Despite its malignant presentation, lues maligna lesions respond rapidly to treatment with penicillin. Secondary syphilis should be added to the list of diseases known to be more aggressive in HIV-infected patients.

Adult↗
PubMed1994

A procedure for RT-PCR amplification of mRNAs on histological specimens.

Detection in combination with localization of low copy gene expression can be difficult to achieve. The use of reverse transcription PCR on tissue sections with a fluorescent marker provides localization of mRNA expression on a cellular level, and when combined with confocal microscopy and image analysis it also allows for an estimate of the relative intensity of fluorescence. A good example of the application of this method is the localization of nerve growth factor (NGF) mRNA expression in the inner ear. NGF through indirect tests appears to be present in this system, yet NGF mRNA could not be localized with in situ hybridization using radiolabeled riboprobes. Using fluorescent in situ RT-PCR, we can easily detect the presence of NGF mRNA and localize it to specific cell types within the maturing inner ear.

Animals↗
PubMed1993

Maternofetal transmission of human immunodeficiency virus-1: the role of antibodies to the V3 primary neutralizing domain.

The increase in the number of human immunodeficiency virus-1 (HIV-1)-infected children is a direct consequence of the heterosexual spread of the disease to women and the growing number of HIV-positive i.v. drug users. It is not known how the majority of infants born to HIV-1-infected women escape HIV-1 infection, and, for those infected, the timing of HIV-1 transmission has yet to be determined. In addition, the role of maternal antibodies in the prevention of HIV-1 transmission to the fetus is unclear. We have previously demonstrated a correlation between vertical transmission and the absence of high-affinity/avidity antibodies to a peptide, KRI-HIGPGRAFYT, which corresponds to a region of the primary neutralizing domain of the gp120 V3 loop of HIVMN (MN-PND). The present study examines the correlation between the presence of these high affinity antibodies in women completing a pregnancy or undergoing an elective abortion and the detection of HIV-1 infection in their aborted fetuses. In several instances, transmission occurred despite high-affinity antibodies to the MN-PND. We have, therefore, evaluated the reactivity of sera to different MN-PND variants. In one infant born to a mother with high-affinity/avidity antibodies to KRI-HIGPGRAFYT (classic MN-PND), the infected baby developed antibodies to an MN-PND variant peptide against which his mother did not mount a humoral immune response during pregnancy. This finding indicates that fetal infection with MN-PND escape mutants arising during pregnancy may occur during a period when the mother is serologically negative.

Amino Acid Sequence↗
PubMed1993

Impact of elderly mother's death on middle age daughters.

Daughters' responses to an elderly mother's death are found to be multidimensional. In the first six months of bereavement many daughters experience themes of both holding on and letting go. Measured were depression, grief, somatic reactions, as well as impact on the sense of self, degree of acceptance of the death, and ways in which the tie with the mother endures. Though many of these reactions are intercorrelated, they are differentially associated with characteristics of the daughter, mother, and the quality of their relationship. Relatively sudden deaths were associated with more intense grief, less acceptance, and more thoughts of reunion than deaths that occurred in a nursing home.

Adaptation, Psychological↗
PubMed1993

Registration and display of multimodal images: applications in the extracranial head and neck region.

Image registration is a correlation procedure that allows the matching of images obtained by different imaging modalities, both structural and functional. Once registered, they can be combined in a single "fused" image. This technique can be used to improve the interpretation and the quantification of relatively low resolution images obtained in nuclear medicine or to achieve a better diagnosis and treatment planning when high resolution anatomical images are registered. Matching images obtained by different imaging modalities is a major challenge and the various registration techniques are briefly described. The extracranial head and neck region is a challenging field for image registration. A preliminary retrospective experience is presented emphasizing the technique feasibility in a routine clinical context. 2-D and 3-D approaches were used. The requirements for transferring registration technology from the image processing laboratory to clinical practice are discussed, and the contribution of this method to medical interdisciplinary communication is emphasized.

Aged↗
PubMed1993

Robust and inexpensive equipment design for polymerase chain reaction detection of sequence mutations. Cystic fibrosis in a mother and 2 children analysed.

Every polymerase chain reaction (PCR) requires use of a temperature cycler for about 3 hours. Since there are many diagnostic tests using this technology, it is important that robust but inexpensive machinery is available. Such a stand-alone machine has been designed and used to analyse an interesting family in which a mother and her 2 children were diagnosed as having cystic fibrosis.

Adult↗
PubMed1992

Inhibition of choline efflux results in enhanced acetylcholine synthesis and release in the guinea-pig corticocerebral synaptosomes.

Synthesis and release of [3H]acetylcholine ([3H]ACh) were measured in synaptosomes from the guinea pig cerebral cortex after preloading with [3H]choline ([3H]Ch). We demonstrate here that inhibition of choline (Ch) efflux results in an increase in acetylcholine (ACh) synthesis and release. Our findings are as follows: (1) inhibition of [3H]Ch efflux by hemicholinium-3 (HC-3) (100 microM), increased the levels of both the released (116% of control) and the residing (115% of control) [3H]ACh. (2) The muscarinic agonist, McN-A-343 (100 microM), which was previously shown to inhibit Ch efflux, also increased the released (121% of control) and the residing (109% of control) [3H]ACh. (3) Omission of Na+ ions (which are required for Ch transport) from the incubation medium had similar effects to those observed with McN-A-343 and HC-3. These results suggest inverse relationships between Ch efflux on one hand, and ACh synthesis and release on the other hand. (4) Depolarization with 50 mM K+, or with the K+ channel blocker, 4-aminopyridine (100 microM), also increased the total level of [3H]ACh (113 and 107% of nondepolarized synaptosomes, respectively). However, whereas conditions that inhibit Ch transport such as HC-3, McN-A-343 and "no sodium" increased both the residing and the released [3H]ACh depolarization with high K+ or 4-aminopyridine reduced the residing (79 and 87% of control, respectively) and increased only the released [3H]ACh (182 and 148% of control, respectively).(ABSTRACT TRUNCATED AT 250 WORDS)

(4-(m-Chlorophenylcarbamoyloxy)-2-butynyl)trimethy↗
PubMed1992

Lack of agonistic activity in McN-A343 may be circumstantial.

1. In Tyrode (Ca++ 1.80 mM) or Krebs (Ca++ 3.36 mM) solution, McN-A343 evoked a dose-dependent contractile response in the naive guinea-pig ileum in the dose range 0.40-40 microM, or bladder in the dose range 0.8-200 microM. 2. After two full cycles of carbachol or bethanechol administration in Tyrode solution, neither preparation responded to McN-A343 for 45 to 60 min. The response in Krebs solution, however, was almost unaltered at 15-30 min. The rate of recovery of the contractile response appears to depend on the calcium content of the medium used. 3. A previous report that McN-A343 failed to evoke a contractile response in the guinea-pig ileum or bladder must be reconsidered in the light of the present findings.

(4-(m-Chlorophenylcarbamoyloxy)-2-butynyl)trimethy↗
PubMed1991

Recurring theme of changes in the transcriptional control region of BK virus during adaptation to cell culture.

BK virus, when cloned directly from human urine, shows no amplification in the transcriptional control region, unlike cell culture-passaged strains, but possesses an additional sequence element. To confirm our proposal that this represents the archetypal in vivo form of the virus, we passaged this BK virus through cell culture. Changes in the transcriptional control region occurred as early as the first passage and were characterized in all cases by a deletion followed by amplification events.

BK Virus↗