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Biomedical subjects

H Hoffman

Publications and source records attributed to H Hoffman.

At least 55 records · Page 3Linked to original sources
PubMed1990

Decreased L system amino acid transport and decreased gamma-glutamyl transpeptidase are independent processes in human chronic lymphocytic leukemia B-lymphocytes.

The L system of amino acid transport is markedly diminished in chronic lymphocytic leukemia (CLL) B-lymphocytes, with a maximal velocity less than 15% that of normal B-lymphocytes. Another membrane-associated function, the activity of the ectoenzyme, gamma-glutamyl transpeptidase (GGT), is diminished in CLL B-cells to 30% that of normal B-cells. In addition to its transpeptidase activity, a role for GGT has been postulated in the transport of amino acids. In the present report, the possible relationship of these two physiologic functions CLL B-cells was studied. The L system transport defect in CLL is restored by phorbol ester-induced cell maturation; following incubation with 0.15 microM tetradecanoyl phorbol acetate (TPA) for 17 hours, the L system initial velocity showed a 20-fold increase. In contrast, there was no significant effect on GGT activity with cell maturation. Furthermore, an antibody which diminished GGT activity by 50% in lymphoid cells did not inhibit L system transport. Thus, the impaired L system amino acid transport and GGT activity appear to be independent processes in CLL B-cells.

Amino Acids↗
PubMed1990

Prevalence of seasonal affective disorder at four latitudes.

The Seasonal Pattern Assessment Questionnaire (SPAQ) was mailed to a sample population balanced for sex and randomly selected from local telephone directories in four areas: Nashua, NH, New York, NY, Montgomery County, MD, and Sarasota, FL. On the basis of responses to this questionnaire, prevalence rates of winter seasonal affective disorder (winter SAD), summer seasonal affective disorder (summer SAD), and subsyndromal winter SAD were estimated for the four areas. Rates of winter SAD and subsyndromal SAD were found to be significantly higher at the more northern latitudes, while no correlation was found between latitude and summer SAD. The positive correlation between latitude and prevalence of winter SAD applied predominantly to the age groups over 35.

Adult↗
PubMed1990

Pineal region germinomas in childhood treatment considerations.

From 1967-1986, 21 children were treated for pineal germinoma, including 16 biopsy-proven, 2 biopsy non-diagnostic, and 3 metastatic unbiopsied (marker negative) patients. Ten of 18 (56%) biopsied patients underwent partial or sub-total tumor resection. Twenty patients were irradiated, 19 of whom are alive. No irradiated patient died of progressive germinoma, but two patients relapsed in the spinal cord and required treatment intensification for salvage. Long-term survivors have significant morbidity. Determination of the minimum effective treatment remains the chief therapeutic challenge.

Adolescent↗
PubMed1990

Posterior fossa medulloblastoma in childhood: treatment results and a proposal for a new staging system.

Seventy-two children with posterior fossa medulloblastoma were diagnosed at the Hospital for Sick Children, Toronto, from 1977 to 1987 and treated by standard methods. The 5- and 10-year survival and disease-free survival rates were 71% and 63%, and 64% and 63%, respectively. Total tumor resection, as determined by the surgeon was the most significant favorable prognostic factor. Post-operative meningitis, a residual enhancing mass lesion on the post-operative, pre irradiation CT scan and dissemination to the brain or cord at diagnosis were unfavorable factors. These four easily definable factors were used to define a staging system with prognostic significance. Five-year disease-free survival rates were for Stage I (total resection, no adverse factor) 100%, Stage II (total resection with one or more adverse factor or less than total resection with no other adverse factor) 78%, and Stage III (less than total resection with one or more adverse factor) 18%. Evaluation of treatment results in medulloblastoma requires that these prognostic factors be known.

Adolescent↗
PubMed1990

Delayed and progressive multiple suture craniosynostosis.

A considerable amount of information is available on various types of craniosynostoses. The patient exhibiting single suture synostosis that progresses to involve multiple sutures is distinctly uncommon, as is the patient exhibiting delayed synostosis involving all of the calvarial sutures. We report a group of 11 such patients with progressive and delayed holocalvarial synostosis. Most patients exhibited features of raised intracranial pressure or developmental delay, and in all patients symptoms were relieved after surgery. The diagnostic and therapeutic implications of this type of presentation in craniosynostosis are discussed.

Child↗
PubMed1989

International Collaborative Effort (ICE) on birthweight; plurality; and perinatal and infant mortality. I: Methods of data collection and analysis.

This paper describes the collection and analysis of data by a group of international collaborators (International Collaborative Effort on Perinatal and Infant Mortality) interested in comparative studies on birthweight distributions and reproductive outcome. This is the first of a series of reports on the results of these studies. It gives an account of the countries or states involved, and the collection and characteristics of the data. The countries and states included sixteen of the United States, plus England and Wales, Denmark, Bavaria and North Rhine-Westphalia from the Federal Republic of Germany, Israel, Japan, Norway, Scotland, and Sweden. The data comprised birthweight distributions in 500-gram groups for all births and for singletons separately, for livebirths, stillbirths, first week deaths and, where available, late neonatal and infant deaths, from 1970 up to 1985.

Birth Weight↗
PubMed1987

The dentist's role in the insurance-legal claims process.

The involvement of the clinician in the insurance-legal process is inevitable. A clear documentation and reporting format will facilitate the dentist's participation. Information is presented to prepare the practitioner for his or her role as an expert witness.

Dental Records↗
PubMed1986

Neurite-promoting activity from fetal skeletal muscle: partial purification of a high-molecular-weight form.

Neurite extension from sensory neuroblasts dissociated from chick embryo dorsal root ganglia can be stimulated by precoating the polylysine culture surface with extracts of skeletal muscle from bovine fetuses. The active factor(s) may be partially purified from cytosolic extracts of muscle by chromatography on Sepharose 6B and affinity chromatography on wheat germ agglutinin or Helix pomatia agglutinin columns. Extract concentrations of 10-50 micrograms protein per 1 ml were active in promoting neurite extension when the neurons were cultured without serum or nerve growth factor (beta NGF). However, levels of 1-10 micrograms/ml produced dramatic neurite extension when 10% (v/v) fetal or newborn calf serum or 0.5 ng/ml beta NGF was added to the medium. The biological activity was not blocked by antiserum that was raised against purified mouse laminin and that abolished the neurite-promoting activity of mouse laminin. The activity of the muscle extract was destroyed by trypsin or heparitinase, in contrast to the biological activity of purified mouse laminin, which was not abolished by heparitinase treatment. The activity could be resolved into two broad peaks on a Sepharose 2B column (apparent Mr between 2 X 10(6) and in 10 X 10(6) in native form). Treatment with dithiothreitol was necessary to dissociate the factor for electrophoresis in 4.25% polyacrylamide-SDS gels, revealing three major polypeptide bands at Mr = 160,000, 195,000 and 200,000. This preliminary characterization indicates that the neurite-promoting activity from bovine skeletal muscle tissue consists of a high-molecular-weight complex, one essential component of which is a heparan sulfate.

Animals↗
PubMed1985

Monoclonal antibodies to nerve growth factor from bovine seminal plasma.

Mouse monoclonal antibodies directed against nerve growth factor (beta NGF) from bovine seminal plasma have been isolated and characterized. They are produced by hybridomas derived from Sp2/0.Ag14 myeloma cells and spleen cells from BALB/c mice immunized with beta NGF which was purified by the method of Harper et al. [J. biol. Chem. 257, 8541-8548 (1982)]. Five of these hybridomas can be grown in ascites tumor form and secrete antibodies of the IgG1 or IgG2a subclass. When used to probe the components of seminal plasma extracts or purified beta NGF as separated electrophoretically on SDS gels, the antibodies react with the beta NGF band at Mr = 15,000. The antibodies bind to native bovine beta NGF, but bind very poorly to mouse beta NGF. Antibody exclusion and additive-binding experiments indicate that these antibodies bind to the 1 antigenic domain. The cell receptor binding site is probably not close to this domain, as the antibodies fail to block the biological activity of bovine beta NGF on cultures of dissociated neurons from sensory ganglia. These monoclonal antibodies define a region in which bovine beta NGF is structurally different from the closely related molecule mouse beta NGF.

Animals↗
PubMed1985

[Results of the selectol field study in Austria].

This multicenter study was initiated to assess the efficacy and safety of celiprolol in a large number of hypertensive patients. Patients received a once daily dose of 200 mg celiprolol for the first 3 weeks. If blood pressure was not lowered satisfactorily after this period, the investigator was asked to rise the dose to 300 mg celiprolol or to add a diuretic for the next 3 weeks. The study included 2694 patients, 2311 of whom were evaluable over a period of 3 weeks, 2077 over 6 weeks. On admission 10% showed isolated systolic hypertension, 38% were in WHO I, 35% in WHO II and 17% in WHO III. Hypertension was known for more than 1 year in 57%, for even more than 5 years in 28%. Concomitant diseases were diabetes mellitus, chronic obstructive airways disease, peripheral arteries disease; digitalis comedication in 211 patients. BP was lowered significantly in all degrees of severity of hypertension. There was no obvious connection between efficacy and age nor with duration of disease. Only 229 patients received 300 mg celiprolol during the second period of treatment, 223 patients got additionally a diuretic. Heart rate decreased by a mean of 8 bpm and was lowered mostly in patients with tachycardia. Patients with a heart rate of 60 bpm or below showed a slight increase in heart rate. In no case heart rate fell below 50. Side effects were rare and in most cases not serious. Treatment was discontinued due to suspected side effects in 58 patients only (2.15%). We conclude, that celiprolol is a safe and efficacious drug in the management of hypertension.

Adolescent↗
PubMed1984

Relationship between ejection phase indices of performance and myocardial functions during the development of pressure overload hypertrophy.

The present study examines the temporal relationship between performance of the hypertrophied nonfalling rabbit heart and the contractility of muscles isolated from these same hearts. Ejection phase indices of ventricular function were determined cineradiographically during the development of hypertrophy. Isolated papillary muscle function was examined an average of 8.6 (early), 40.1 (middle), and 97.5 (late) days after banding of the pulmonary artery. Active tension development at Lmax (F) was depressed by 65% in the muscles examined early and by 43% in the middle group. By the late group, F was comparable to control levels. Early depression and a return to normal function were also observed for peak dF/dt and velocity of shortening at Lmax. Time to peak tension was unchanged at 8.6 days and increased at the middle and late time points. Both percentage of shortening and mean normalized velocity of shortening, determined cineradiographically in the intact heart, were depressed immediately following surgery, gradually returned toward "normal function" by the third week, and plateaued at a stable level of performance, which was maintained thereafter. The similarity of in vivo function of the hypertrophied and control hearts, despite the profound differences observed in the myograph, indicate that "ejection phase indices," such as fiber shortening rate, are poor indicators of intrinsic function during the development of hypertrophy. Moreover, these results demonstrate the extent to which intrinsic functional deficits may be overcome in the whole heart and suggest the presence of mechanisms such as enhanced sympathetic nervous activity, which contribute to the maintenance of this normal basal ventricular function.

Animals↗
PubMed1983

[Comparative changes in sedimentation rate, haptoglobin and orosomucoid during the development of rhizomelic pseudopolyarthritis and temporal arteritis. Attempted definition of the biological parameters for monitoring these diseases].

In pseudo-polyarthritis of the extremities as well as in temporal arteritis we have noted a very marked correlation between sedimentation rate (ESR) and inflammatory proteins at the beginning of the disease. By contrast there is a dissociation during the course of the illness and sometimes at the time of onset in those rare forms with a normal ESR. It was therefore concluded that the ESR was not sufficiently accurate as an index of surveillance in such diseases. Study of inflammation proteins is in rare circumstances of diagnostic value at the time of onset of the disorder, in forms with a normal ESR. Comparative study of their variations with that in ESR would appear to provide an accurate factor in surveillance during the course for peripheral pseudo-polyarthritis and temporal arteritis. At that time, even though a return to a satisfactory clinical state and a normal ESR may be accompanied by a persistent increase in such proteins, it is not felt to be desirable to attempt to obtain their normalization. Finally, it would appear that their return to normal at the end of the course of the disease provides a reliable test of cure.

Adrenal Cortex Hormones↗
PubMed1982

[Rhizomelic pseudopolyarthritis and Horton's disease. A search for correlations with HLA system, HB virus and Beta 2 microglobulin (author's transl)].

The authors studied 31 patients with either rhizomelic pseudopolyarthritis or Horton's disease. Contrary to others, they found no significant correlation between these diseases and hepatitis B virus infection or HLA gene. However, beta 2 microglobulin assays showed that it was significantly higher in these patients than in a control population. In the absence of close correlation between beta 2 microglobulin levels and those of inflammatory proteins, it is suggested that the rise in microglobulin reflected an immunological mechanism requiring further investigation.

Aged↗
PubMed1982

[Comparative variations of the sedimentation rate, haptoglobin and orosomucoid in rhizomelic pseudopolyarthritis and temporal arteritis. Attempt at a definition of biological parameters for monitoring these diseases].

In pseudo-polyarthritis of the extremities as well as in temporal arteritis we have noted a very marked correlation between sedimentation rate (ESR) and inflammatory proteins at the beginning of the disease. By contrast there is a dissociation during the course of the illness and sometimes at the time of onset in those rare forms with a normal ESR. It was therefore concluded that the ESR was not sufficiently accurate as an index of surveillance in such diseases. Study of inflammation proteins is in rare circumstances of diagnostic value at the time of onset of the disorder, in forms with a normal ESR. Comparative study of their variations with that in ESR would appear to provide an accurate factor in surveillance during the course of peripheral pseudo-polyarthritis and temporal arteritis. At that time, even though a return to a satisfactory clinical state and a normal ESR may be accompanied by a persistent increase in such proteins, it is not felt to be desirable to attempt to obtain their normalization. Finally, it would appear that their return to normal at the end of the course of the disease provides a reliable test of cure.

Aged↗