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Biomedical subjects

H Kohn

Publications and source records attributed to H Kohn.

At least 55 records · Page 3Linked to original sources
PubMed1988

Neuropsychological deficits in obligatory heterozygotes for metachromatic leukodystrophy.

Two groups of heterozygotes, one for metachromatic leukodystrophy (MLD) and the other for Tay-Sachs disease, were given a battery of neuropsychological tests, a standard neurological examination, and an EEG. Neurological and EEG findings were unremarkable for both groups. The MLD heterozygotes showed deficits in the neuropsychological tests involving spatial or constructional components, but not in tests involving language skills. The Tay-Sachs heterozygotes showed no consistent deficit on any component of the neuropsychological tests.

Electroencephalography↗
PubMed1987

Functionalized DL-amino acid derivatives. Potent new agents for the treatment of epilepsy.

Structural analogues of the potent known anticonvulsant agent N-acetyl-DL-alanine N-benzylamide (1a) have been prepared (16 examples). The pharmacological activities of these products were evaluated in the maximal electroshock seizure (MES), the subcutaneous pentylenetetrazole seizure threshold (sc Met), and the rotorod (Tox) tests. The median effective doses (ED50) and the median toxic doses (TD50) for the most active compounds by both intraperitoneal and oral administration are reported. The most active compounds were N-acetyl-DL-phenylglycine N-benzylamide (1d) and N-acetyl-DL-alanine N-m-fluorobenzylamide (1m) along with the parent compound 1a. The ED50 values in the MES test for these three compounds compared well with phenobarbital, while their high TD50 values contributed to their large protective indexes, which approached that of phenytoin. When tested against four convulsant agents, compounds 1a and 1d displayed activity profiles significantly different from those reported for conventionally used antiepileptic drugs.

Amino Acids↗
PubMed1987

Synthesis and antineoplastic activity of 1a-formyl and 1a-thioformyl derivatives of mitomycin C and 2-methylaziridine.

A select number of 1-formyl- and 1-thioformyl-2-methylaziridine derivatives and the corresponding 1a-substituted mitomycin C analogues were synthesized and tested for antineoplastic activity by using an in vivo test with murine P388 leukemia. Select compounds were also tested in vivo with murine melanoma B16. Several of the mitomycin C derivatives displayed activity and some of the mitomycin C analogues were comparable in activity to the parent compound.

Animals↗
PubMed1985

Effect of structural modification of the hydantoin ring on anticonvulsant activity.

Selectively substituted hydantoins 1 (15 examples), 4-hydroxy-2-imidazolidinones 2 (13 examples), 2-imidazolones 3 (10 examples), 2-imidazolidinones 4 (four examples), vicinal diamines 5 (two examples), and simple amino acid derivatives 6 (four examples) have been prepared and evaluated in the maximal electroshock seizure (MES), subcutaneous pentylenetetrazole seizure threshold (sc Met), and rotorod (Tox) tests. The medium effective doses (ED50) and the medium toxic dose (TD50) for the most active compounds are reported. In general, the most pronounced activity was observed for hydantoins 1 and protected amino acids 6. Within each series of compounds, enhanced anticonvulsant activity was often noted for compounds containing an aromatic group one carbon removed from a nitrogen atom. Among the most active compounds observed were the amino acid derivative N-acetyl-D,L-alanine benzylamide (6d) and the two 2-imidazolones 4-methyl-1-(phenylmethyl)-1,3-dihydro-2H-imidazol-2-one (3e) and 1-phenyl-1,3-dihydro-2H-imidazol-2-one (3g). Compound 6d proved to be slightly more potent in the MES test than phenacemide.

Animals↗
PubMed1982

Assessment of activity in Sarcoidosis. Sensitivity and specificity of 67Gallium scintigraphy, serum ACE levels, chest roentgenography, and blood lymphocyte subpopulations.

The value of different factors are examined to assess activity in 60 patients with biopsy-proven sarcoidosis. In patients with active sarcoidosis (n = 35), 67Gallium scans proved to be the most sensitive method (94 percent sensitivity), followed by serum angiotensin I converting enzyme (S-ACE) levels, chest x-ray films, and lymphocyte assays. In patients with peripheral pulmonary lesions, chest x-ray films failed in 32 percent of cases to document activity (68 percent sensitivity) whereas 67Ga scans and S-ACE levels remained to give reliable results. Despite poor specificity, negative 67Ga scans together with normal ACE levels have a high predictive value for exclusion of active sarcoidosis. In patients with peripheral pulmonary lesions, chest roentgenography is of doubtful value for staging lung involvement and assessment of activity including monitoring and control of therapy.

Adolescent↗
PubMed1978

Syntheses and pharmacological activity of N-acyl-substituted imidazolidinethiones and thioimidazolines.

A series of imidazolidinethiones and thioimidazolines was synthesized and tested for their effect on both forced and spontaneous motor activities as well as their ability to raise the convulsion threshold. The N-acyl-substituted 2-p fluorobenzylthioimidazolines were the most active compounds, producing protection against maximal electroshock seizures and tonic convulsions induced by pentylenetetrazol. Both compounds had high LD50 values and safety indexes.

Animals↗
PubMed1978

Clinical course of adult metachromatic leukodystrophy presenting as schizophrenia. A report of two living cases in siblings.

Adult metachromatic leukodystrophy is a demyelinating disease due to an inherited lack of arylsulfatase A activity. The purpose of this paper is to present the characteristics of this disorder as they occurred chronologically in two siblings, prior to and subsequent to the appearance of gross neurological deficits. A deficit in spatial relationships, as contrasted with verbal abilities, was observed initially in both cases at age 13. Initial psychiatric symptoms were noted at age 16 and 18, with both patients being diagnosed subsequently as schizophrenic. Gross neurological deficits were observed 2 and 13 years, respectively, after the appearance of psychiatric symptoms. A deficit in spatial relationships may be a very sensitive early indicator of adult metachromatic leukodystrophy.

Adolescent↗
PubMed1977

Mutation in a new H-2-associated histocompatibility gene closely linked to H-2D.

Sequential precipitations of soluble BALB/c antigen with antisera detecting private and public H-2 specificities indicated three distinct classes of molecules of 45,000 mol wt. However, only two of these classes of molecules were detectable in antigen from the loss mutant, BALB/c-H-2db. The class of molecules, detectable in the wild-type strain but missing in the mutant, does not bear private specificities but does react with an antiserum detecting H-2 public specificities. Absorption in mutant mice of the antiserum to public specificities, left antibodies specific for the antigen detectable in BALB/c but not BALB/c-H-2db. Genetic mapping studies using this specific antiserum indicated that the antigenic loss of this mutant is in a gene which maps in or close to the H-2D region, separable from the H-2K, S, G, Qa-2, and Tla regions.

Animals↗
PubMed1977

Syntheses and pharmacological activity of substituted imidazolidinethiones and thiomidazolines.

A series of imidazolidinethiones and thioimidazolines was synthesized and tested for their effects on both forced and spontaneous motor activity as well as for their ability to raise the convulsion threshold. The proton NMR spectra for the thioimidazolines synthesized were unusual in that they showed a sharp singlet for the ring ethylene unit rather than the expected A2B2 pattern. The thioimidazolines, 5 and 7, were the most active CNS depressants and had the highest safety index. Significantly, the isomeric imidazolidinethiones, 8 and 9, were comparatively much less effective while being considerably more toxic.

Animals↗
PubMed1966

Interrelations between photoperiod, frost hardiness and sulfhydryl groups in cabbage.

Hardening of SD (8 and 12 hrs) and LD (18- and 24-hr photoperiods) cabbage plants in stages at temperatures starting with + 5 degrees and ending with - 3 degrees led to the following changes:Soluble protein plus nonprotein N showed a net increase only in the SD plants. In both SD and LD plants, it decreased to a minimum toward the end of the first stage of hardening, increased to a maximum in the second stage. The degree of this change was proportional to the photoperiod. These changes were mainly due to the proteins.As in previous investigations, SH content rose during the first 1 to 2 weeks, but only in the SD plants. This rise was primarily due to the protein fraction. After the first 1 to 2 weeks both SD and LD plants showed a decrease in SH content, most pronouncedly during the second stage of hardening.Nonprotein SH content was very low and decreased during hardening in both SD and LD plants. Nonprotein SS increased during the first stage of hardening. Total nonprotein SH+2SS rose to a maximum during the first stage of hardening, paralleling both osmotic potential and hardiness. During the second stage the total decreased, in spite of the rise in hardiness. These results held true for both SD and LD plants.These results are all explainable on the basis of the SHright harpoon over left harpoonSS theory of frost resistance.

Journal Article↗