Biomedical subjects
Publications and source records attributed to M Boss.
The antimonide oxide Ba(3)Sb(2)O consists of discrete [Sb(2)](4-) and O(2-) anions, and crystallizes with a new structure type. The Sb-Sb distances are comparable to those known from electron-precise zintl phases and the tetrahedral coordination of the O(2-) anion is also observed in some other Ba-rich metallide oxides.
BACKGROUND: Machado-Joseph disease (MJD), also known as spinocerebellar ataxia type 3 (SCA3), can present with parkinsonism. However, classically, atypical features, including pyramidal and cerebellar signs, peripheral neuropathy, and/or anterior horn cell dysfunction, are also seen. Levodopa responsiveness is unusual in this disorder. OBJECTIVE: To determine the cause of apparent parkinsonism suggestive of Parkinson disease (PD) in a large family of African origin. METHODS: We studied a large family in which apparent autosomal dominant parkinsonism suggestive of PD occurs in order to find the causal genetic mutation. Affected and unaffected family members were screened for the presence of a pathogenic expansion at the MJD/SCA3 locus using a polymerase chain reaction polyacrylamide gel electrophoresis-based assay. RESULTS: Three of the 4 individuals who were examined have a phenotype reminiscent of PD. Specifically, they have at least 2 of the cardinal features, are levodopa responsive, and have no atypical features. All affected family members were shown to possess pathogenic expansions in the MJD/SCA3 gene. CONCLUSIONS: Parkinsonism suggestive of PD due to MJD/SCA3 has not been previously reported, to our knowledge. However, atypical, though also levodopa-responsive, parkinsonism has been previously reported to occur in African American families, suggesting that that this phenotype is associated with African ancestry. In this regard, it is perhaps significant that all the individuals with parkinsonism have relatively low numbers of repeats (normal, 16-34; pathologic, 60-84). In families in which linkage analysis is being performed to determine a locus for autosomal dominant parkinsonism suggestive of PD, evaluation for the MJD/SCA3 mutation is indicated.
OBJECTIVE: To describe the clinical and molecular genetic analysis of a large family of northern Chinese descent with a mutation at the SCA2 locus causing carbidopa-levodopa-responsive parkinsonism. BACKGROUND: Most causes of parkinsonism remain unknown. However, molecular genetic analysis of families with parkinsonism has recently identified five distinct loci and pathogenic mutations in four of those. Additionally, some of the spinocerebellar ataxia syndromes (SCA), particularly Machado-Joseph syndrome (SCA3), are known to cause parkinsonism. Spinocerebellar ataxia type 2 (SCA2) has not previously been described as causing a typical dopamine-responsive asymmetric PD phenotype. METHODS: A large family was evaluated clinically and molecularly for apparent autosomal dominant parkinsonism. RESULTS: The phenotype includes presentation consistent with typical dopamine-responsive parkinsonism. Other presentations in this family include a parkinsonism/ataxia phenotype, which is classic for SCA2 and parkinsonism, resembling progressive supranuclear palsy. CONCLUSIONS: Patients presenting with a family history of parkinsonism, including familial progressive supranuclear palsy and PD, should be tested for the spinocerebellar ataxia type 2 expansion.
As the modern treatment for anal carcinoma is either radiotherapy alone or combined radiochemotherapy, an exact histological staging is impossible. Therefore we have to depend on an accurate preoperative staging method. Endoanal ultrasonography enables imaging of the normal anal canal and its pathologies. In a prospective investigation we were able to confirm the histological proven diagnosis of an anal epidermoid carcinoma in 12 patients with a 10-MHz transducer covered with a sonolucent plastic cone. The depth of infiltration can be determined in relation to the normal layers of the anal canal. Six patients treated with radiotherapy alone or combined radiochemotherapy were followed and the success or failure of the treatment was documented. Endosonography of the anal canal allows an exact staging of a primary anal carcinoma and the follow-up in irradiated carcinomas. Besides digital palpation and proctoscopy with biopsy, endosonography complements the preoperative staging of anal carcinomas.
Endorectal ultrasound is the most reliable method in staging rectal cancer and is superior to computed tomography. In a prospective series of 152 consecutive patients, comparison of preoperative ultrasound staging and postoperative histopathological staging resulted in an overall accuracy of 90.1%. Overstaging was observed in 9.2%, understaging in 0.7%. Peritumoral inflammatory changes, preoperative radiotherapy and localization of the tumor in the lower rectum were the main reasons for overstaging. Understaging was seen in stenotic or only minimal invasive tumors. Accuracy in staging lymph nodes was 78.5%. Inflammatory changes in the nodes were responsible for either overstaging or understaging. Whether diagnosis will be improved with a higher frequency--mainly in lymph nodes--has yet to be proved. With knowledge of the reasons for misinterpretation, endorectal sonography is--mainly in the lower rectum--a valuable aid in evaluation of surgical procedure.
Staff nurses are expected by nurse administrators and educators to incorporate nursing theory, diagnosis and researched-based interventions into highly technical patient care. However, there has been minimal systematic observation of how nurses learn in clinical practice and how that learning could be enhanced. Recently, an exploratory study was conducted to start filling that gap.
The endoluminal sonography is a new investigation in staging rectal cancer. In a prospective series the value of the endoluminal sonography is compared with clinical staging and computed tomography. The accuracy in clinical staging, computed tomography and endoluminal sonography was 77%, 76% and 87%, respectively. The reasons for under- and overstaging and the interpretation of perirectal lymph nodes are discussed. The endoluminal sonography is an important new method evaluating the operative procedure of cancers in the lower rectum.
In the healthy human adult, body iron content is regulated by intestinal iron absorption. However in neonates who are iron replete, iron absorption is inappropriately increased. In this study we have compared the kinetics of iron absorption in the proximal small intestine of the newborn and adult guinea pig in order to gain insight into the cellular mechanisms underlying this difference. Iron uptake was studied in vivo over the concentration range 20-2,000 microM. Total iron uptake could be resolved into saturable and linear components. The kinetic constants for the saturable component in the adult were similar to the neonate. In contrast, the rate of uptake via the linear pathway was 4 times greater in the neonate compared to the adult. It is concluded that the increased absorption of iron by the neonatal guinea pig is due to an enhanced uptake via the linear pathway. In contrast to total iron uptake, we were unable to detect developmental changes in iron transfer into the carcass.
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The use of reciprocal peer teaching (RPT) was evaluated by 66 first-year medical students participating in gross anatomy laboratory sessions at the University of Ottawa Faculty of Health Sciences. In RPT each student in turn served as a teacher of his peers. The students compared RPT with staff teaching, and almost all reported that they acquired as much knowledge of topics taught by their peers and greater knowledge of topics that they taught personally than they acquired from staff teaching. In addition, most students reported improved study habits, better attitudes toward anatomy, and more independent study. A majority of the students felt they would be better able to communicate with patients and felt more like students of medicine than before participating in RPT. The authors concluded that the active involvement of students in teaching will help prepare students to be continual and independent self-learners throughout their professional careers.
To confirm recent observations that some vitamin D deficient osteomalacic patients had low plasma creatinine concentrations, low urinary creatinine excretion, and a paradoxically low creatinine clearance, and whether these changes were due to vitamin D deficiency per se, these measurements were made in patients before and after vitamin D supplementation. The pretreatment levels were also compared with those in healthy controls and in non-osteomalacic patients without renal disease. The above changes were confirmed. After treatment with vitamin D, plasma creatinine concentrations rose, but urinary creatinine excretion and creatinine clearance did not alter. These data indicate the limitation of creatinine clearance as an index of renal function in vegetarian osteomalacic patients. Furthermore, they demonstrate the effect of vitamin D deficiency and its reversal on plasma creatinine concentrations.
The immunoglobulin heavy chain variable region is encoded as three separate libraries of elements in germ-line DNA: VH, D and JH. To examine the order and regulation of their joining, we have developed assays that distinguish their various combinations and have used the assays to study tumor cell analogs of B-lymphoid cells as well as normal B-lymphoid cells. Abelson murine leukemia virus (A-MuLV) transformed fetal liver cells - the most primitive B-lymphoid cell analog available for analysis - generally had DJH rearrangements at both JH loci. These lines continued DNA rearrangement in culture, in most cases by joining a VH gene segment to an existing DJH complex with the concomitant deletion of intervening DNA sequences. None of these lines or their progeny showed evidence of VHD or DD rearrangements. Heavy chain-producing tumor lines, representing more mature stages of the B-cell pathway, and normal B-lymphocytes had either two VHDJH rearrangements or a VHDJH plus a DJH rearrangement at their two heavy chain loci; they also showed no evidence of VHD or DD rearrangements. These results support an ordered mechanism of variable gene assembly during B-cell differentiation in which D-to-JH rearrangements generally occur first and on both chromosomes followed by VH-to-DJH rearrangements, with both types of joining processes occurring by intrachromosomal deletion. The high percentage of JH alleles remaining in the DJH configuration in heavy chain-producing lines and, especially, in normal B-lymphocytes supports a regulated mechanism of heavy chain allelic exclusion in which a VHDJH rearrangement, if productive, prevents an additional VH-to-DJH rearrangement.
The effect of copper chelation was studied in a group of children with intrahepatic cholestasis of childhood (IHCC) and increased liver copper levels. Initial therapy was D-penicillamine (10 mg/kg/day), being replaced by triethylenetetramine dihydrochloride (20 mg/kg/day) when side-effects of D-penicillamine occurred. Eight children completed two years of copper chelation. Pruritus remained the main symptom and did not improve. Two patients developed D-penicillamine side-effects - one patient after nine months (marked anorexia, lassitude) and one other patient after 19 months (thrombocytopenia). Two patients died during the study, in one of these normal hepatic copper concentration was achieved. Hepatic copper concentrations decreased in seven of eight patients from 8.6 (2.7 +/- 16.2) mumol/g to 3.4 (0.6-16.5) mumol/g (median and range (0.05 less than 0.01) and serum aspartate transaminase increased in seven of eight patients (p less than 0.05). Histological assessment of serial liver sections revealed increased fibrosis and cholestasis despite reductions in hepatic copper levels during the study. This study showed that D-penicillamine therapy was associated with significant side-effects, while marked clinical, biochemical, or histological improvement did not follow effective copper chelation therapy in intrahepatic cholestasis of childhood.
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The effect of clemastine fumarate, a histamine H1-antagonist, on the potentiation of itch by prostaglandin E1 (PGE1) was studied in normal humans. The antihistamine drug did not abolish the potentiation, which suggests that the effect of PGE1 on itch does not depend on the liberation of endogenous histamine.
The appearance of Freud's earliest writings at the beginning of this century marked the birth of modern systematic and scientific psychotherapy. The following development was explosive in its depth and breadth. It was primarily the group psychotherapies that contributed most to the development in breadth. They practised the reverse of Freud's basic teaching that the whole healing process should occur within a psychic realm. A development in depth was not possible until a reflective review of the presuppositions of psychotherapy concerning the nature of the human being was admitted. Prior to this, the rapidly appearing new schools of psychotherapy were superficial and even thoughtless in their basic tenets. Ludwig Binswanger's thinking initiated a new approach to the understanding of the basic condition and meaning of human existence. Following the example of the philosopher Martin Heidegger, he was able to replace the name of what had previously been called "psychotherapy" with the designation "Daseinsanalyse". It then became possible to give up the ever vague and opaque conception of a "psyche" in favour of the strictly scientifically defined "Da-sein" of the human being.
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