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Biomedical subjects

T Kaufmann

Publications and source records attributed to T Kaufmann.

At least 19 recordsLinked to original sources

Region-specific encoding of sensory and affective components of pain in the human brain: a positron emission tomography correlation analysis.

Brain imaging with positron emission tomography has identified some of the principal cerebral structures of a central network activated by pain. To discover whether the different cortical and subcortical areas process different components of the multidimensional nature of pain, we performed a regression analysis between noxious heat-related regional blood flow increases and experimental pain parameters reflecting detection of pain, encoding of pain intensity, as well as pain unpleasantness. The results of our activation study indicate that different functions in pain processing can be attributed to different brain regions; ie, the gating function reflected by the pain threshold appeared to be related to anterior cingulate cortex, the frontal inferior cortex, and the thalamus, the coding of pain intensity to the periventricular gray as well as to the posterior cingulate cortex, and the encoding of pain unpleasantness to the posterior sector of the anterior cingulate cortex.

Adult

The human complement C9 gene: identification of two mutations causing deficiency and revision of the gene structure.

The ninth component of human complement (C9) is the last of the terminal complement components creating the membrane attack complex. C9 is a single-chain serum protein that is encoded by a gene located on chromosome 5p. Deficiency of terminal complement components is generally associated with recurrent neisseria infections. We studied a previously described Swiss family with inherited C9 deficiency. To identify the genetic basis of C9 deficiency, we developed an approach using exon-specific PCR and direct DNA sequencing. As a cause of C9 deficiency, we found two different point mutations, both generating TGA stop codons in the coding sequence. One mutation, a C to A exchange, was detected in exon 2 at cDNA position 166, the other, a C to T exchange, was located in exon 4 (cDNA position 464). In family studies of three first-degree relatives with heterozygous C9 deficiency, we demonstrated that the two mutations are segregating independently. Therefore, these mutations are sufficient to explain the complete deficiency of both the probands studied. DNA sequencing of the exon-intron junctions revealed a number of revisions regarding the boundaries between exons 4, 5, and 6 as well as between exons 10 and 11. No additional introns were detected in exons 6 and 10. Furthermore, DNA marker studies were conducted using known polymorphisms of the C6, C7, and C9 genes, confirming the linkage of the observed C9 mutations with defined haplotypes.

Base Sequence

CODBLAM IV chemotherapy for large cell lymphoma: sequential use of infusional vincristine and bleomycin and "high dose" consolidation.

BACKGROUND: Based on prior results in large cell lymphoma (LCL) with COPBLAM (Cyclophosphamide, Oncovin, Prednisone, Bleomycin, Adriamycin, Matulane) I and COPBLAM III, CODBLAM (Cyclophosphamide, Oncovin, Dexamethasone, Bleomycin, Adriamycin, Matulane) IV was developed to intensify treatment further by utilizing four sequential cycles of infusional chemotherapy followed by high-dose chemotherapy and cycle active agents. METHODS: Sixty-one patients with LCL, mostly B-cell lymphoma, with 54% >60 years of age, were treated with daily continuous infusion of vincristine 1.0 mg/m2 days 1-2, bleomycin 4 mg/m2 i.v. push x 1 only followed by daily infusion 4 mg/m2 days 1-5, dexamethasone 10 mg/m2 days 1-5, procarbazine 100 mg/m2 orally days 1-5, doxorubicin 35 mg/m2 i.v. push day 1 (escalated), and cyclophosphamide 350 mg/m2 i.v. push day 1 (escalated), all given every 3 weeks for four cycles. After infusions, patients were restaged and treated with single courses of doxorubicin 90 mg/ m2 i.v. push followed at 3 weeks with cyclophosphamide 1500 mg/m2 i.v. push (both with concomitant vincristine 1 mg/m2 i.v. push and dexamethasone 10 mg/m2 p.o. daily for 5 days). Remaining treatment consisted of methotrexate 120 mg/m2 i.v. push with citrovorum rescue, cytarabine 250 mg/m2 i.v. push, and etoposide 100 mg/m2 i.v. infusion over 1 h, all given every 10 days for six cycles. RESULTS: The overall complete response (CR) rate was 88%. Of all patients, 36 (59%) are sustained disease free at a median follow-up time of 55 months. In patients age < or = 60 years, 89% achieved CR and 85% of patients age >60 years attained CR. CR was achieved in 83% of patients with constitutional B-type symptoms, 69% of patients with bulky adenopathy, and 86% of patients with immunoblastic histology. Toxicity was primarily pulmonary, occuring in 15% of patients. One toxic death was observed. CONCLUSIONS: Infusional CODBLAM IV may represent an effective and unique treatment for LCL.

Adult

A comparison of survival of patients treated for AIDS-related central nervous system lymphoma with and without tissue diagnosis.

PURPOSE: This is a retrospective review of the treatment outcome of radiation therapy (RT) in acquired immune-deficiency syndrome (AIDS) patients with presumed primary central nervous system (CNS) non-Hodgkin's lymphoma (NHL), with and without tissue verification. METHODS AND MATERIALS: Twenty-seven patients with AIDS-related CNS NHL were treated between 1986 and 1992. They were divided into two groups. Group 1 consisted of nine patients with a positive histology for NHL. They were treated with dexamethasone (DXM) and whole brain RT. Group 2 consisted of 18 patients who, because of unique circumstances, were treated without histologic confirmation of NHL. Rapid clinical and/or radiologic response to DXM and whole-brain RT was interpreted as NHL. RESULTS: For group 1, the response rate was 87.5%, mean survival 6.1 months, and median survival 4.5 months. For group 2, the response rate was 72.2%, mean survival 5.2 months, and median survival 4.5 months. The overall response rate was 76.9%, mean survival 5.8 months, and median survival 4.5 months. CONCLUSIONS: In instances where a tissue diagnosis cannot be established, a positive response to an empiric trial of DXM and RT to 20 Gy may constitute presumptive evidence of NHL.

Antineoplastic Agents, Hormonal

Case report: Kaposi's sarcoma of the rectum--treatment with radiation therapy.

The number of patients afflicted with the acquired immune deficiency syndrome (AIDS) is on the rise. About 30% of AIDS patients develop Kaposi's sarcoma. Although the skin is the most common site of involvement, lesions may encompass the gastrointestinal tract. The purpose of this report is to describe a patient with AIDS related Kaposi's sarcoma of the rectum, successfully treated with radiation therapy. We believe this to be a useful technique in the treatment of this condition.

Acquired Immunodeficiency Syndrome

The eighth component of human complement: molecular basis of C8A (C81) polymorphism.

Using an exon-specific polymerase chain reaction (PCR) followed by direct DNA sequence analysis we have analyzed the polymorphism of the alpha-chain of the eighth component of human complement (C8) at the DNA level. We found that two common alleles, C8A*A and C8A*B, are characterized by the substitution of a single amino acid (Gln to Lys), which is caused by a point mutation of a single nucleotide (C to A) in exon 3 at position 187 of the mature C8 alpha cDNA sequence. Based on this mutation, an allele-specific PCR was designed detecting the two alleles of C8A. We applied this method to type the C8A polymorphism using DNA samples from a Chinese Han population. The comparison with the data of protein typing of the same samples proved that the described method is efficient and reliable for the identification of C8A genotypes and may be valuable for further application in population studies and forensic science.

Alleles

Interaction of sulfhydryl reactive reagents with components involved in (1,3)-beta-glucan synthesis from Candida albicans.

Glucan synthesis was sensitive to several sulfhydryl reacting compounds: mercurials, reversible disulfides, and an alkylating sulfhydryl reagent (IC50 3-45 microM). Thiol groups associated with glucan synthesis were hydrophilic in nature, since both hydrophilic and hydrophobic reagents were active. Glucan synthase complex consists of at least two components: a peripheral GTP-binding protein that can be solubilized with detergents (supernatant) and the catalytic membrane-bound component (pellet). A rapid separation technique was developed to study sulfhydryl interactions with the complex. The GTP-binding protein was solubilized with 0.6% 3-((3-cholamidopropyl)dimethylammonio)-1-propane sulfonate from isolated microsomes of Candida albicans cells grown at either 10 or 30 degrees C. The residual membranous fraction contained the core catalytic moiety of glucan synthase. Both fractions were devoid of glucan synthase activity until they were reconstituted by mixing the two fractions together. In reconstitution experiments, the pellet lost almost 50% activity when preincubated with 2.5 microM N-ethylmaleimide and combined with an untreated supernatant whereas only 10% activity was lost when the supernatant was treated with N-ethylmaleimide. The catalytic active site of glucan synthase was not protected with UDP-Glc when preincubated with 10 microM N-ethylmaleimide but the GTP-binding fraction was partially protected with GTP gamma S.

Candida albicans

Genetic basis of human complement C8 beta deficiency.

The eighth component of human complement (C8) is a serum protein consisting of three chains (alpha, beta, and gamma) and encoded by three different genes, C8A, C8B, and C8G. C8A and C8B are closely linked on chromosome 1p, whereas C8G is located on chromosome 9q. In the serum the beta subunit is non-covalently bound to the disulfide-linked alpha-gamma subunit. Patients with C8 beta deficiency suffer from recurrent neisserial infections such as meningitis. Exon-specific polymerase chain reaction (PCR) amplification with primer pairs from the flanking intron sequences was used to amplify all 12 C8B exons separately. No difference regarding the exon sizes was observed in a C8 beta-deficient patient compared with a normal person. Therefore, direct sequence analysis of all exon-specific PCR products from normal and C8 beta-deficient individuals was carried out. As a cause for C8 beta deficiency, we found a single C-T exchange in exon 9 leading to a stop codon. An allele-specific PCR system was designed to detect the normal and the deficiency allele simultaneously. Using this approach as well as PCR typing of the Taql polymorphism located in intron 11, five families with 7 C8 beta-deficient members were investigated. The mutation was not found to be restricted to one of the two Taql RFLP alleles. The mutant allele was observed in all families investigated and can therefore be regarded as a major cause of C8 beta deficiency in the Caucasian population. In addition, two C8 beta-deficient patients were found to be heterozygous for the C-T exchange. The molecular basis of the alleles without this point mutation also causing deficiency has not yet been defined.

Base Sequence

The human complement component C8B gene: structure and phylogenetic relationship.

The eighth component of human complement (C8) is a serum protein that consists of three chains (alpha, beta and gamma), encoded by three separate genes, viz., C8A, C8B, and C8G. In serum, the beta-subunit is non-covalently bound to the disulfide-linked alpha-gamma subunit. Using a full-length C8 beta cDNA probe, we isolated several clones from human genomic lambda DNA libraries. Four lambda clones covering the complete cDNA sequence were characterized by TaqI restriction mapping and were "shotgun" subcloned into M13. C8 beta-cDNA-positive clones were partially sequenced to characterize the 12 exons of the gene with sizes from 69 to 347 bp. All intron-exon junctions followed the GT-AG rule. By using polymerase chain reaction (PCR) primers located in the adjacent intron sequences, all 12 exons of the C8B gene could be amplified from genomic DNA. All fragments showed the expected sizes. The sizes of eight introns could be determined by using primer pairs that amplified two exons and the enclosed intron, and by restriction mapping. These analyses and the insert sizes of the genomic lambda clones indicate that the C8B gene has a total size of approximately 40 kb. The polymorphic TaqI site of the C8B gene localized in intron 11 could be demonstrated by direct restriction fragment analysis of a PCR fragment containing exons 11 and 12, and the enclosed intron 11. Homology comparison of the C8B gene with C8A and C9 on the basis of the exon structure confirmed the ancestral relationship known from the protein level.

Base Sequence

Lymphomatoid papulosis: case report of a patient managed with radiation therapy and review of the literature.

Lymphomatoid papulosis is an elusive and very rare skin disorder. It is clinically benign but histologically "atypical," and about 20% of affected patients go on to develop a lymphoreticular malignancy, usually Hodgkin's disease, or mycosis fungoides. A wide variety of treatments to prevent recurrence and improve local control have been suggested, but the results have been poor. We report on a patient with two nonhealing lymphomatoid papulosis lesions treated successfully with electron beam therapy and describe our technique. The need for close follow-up of all patients with this condition cannot be overemphasized.

Humans