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Biomedical subjects

M Klein

Publications and source records attributed to M Klein.

At least 271 records · Page 15Linked to original sources
PubMed1996

Massive osteolysis (Gorham-Stout syndrome) in the maxillofacial region: an unusual manifestation.

An unusual case of massive osteolysis affecting the left side of the mandible, the maxilla, the zygoma, and the orbit is reported. The disease extended over a period of 25 years. The special feature of this case is that there were, before the osteolysis appeared, enlargement and sclerosis of the maxillofacial bones reaching up to the middle cranial fossa. Histopathologic examination of the affected mandible revealed that the bone was replaced by fibrous tissue.

Adult↗
PubMed1996

Cloning and characterization of aplycalcin and Aplysia neurocalcin, two new members of the calmodulin superfamily of small calcium-binding proteins.

We report here the sequences of two new proteins from Aplysia, aplycalcin and Aplysia neurocalcin. These proteins belong to a family of calcium-binding proteins, found primarily in vertebrate brain and retina, that have been proposed to play a role in calcium-dependent regulation of enzymes in signal transduction pathways. Like other members of this family, the Aplysia proteins have consensus sequences for myristoylation, bind calcium, and translocate from cytosol to membrane when the calcium level is raised above the resting intracellular concentration. Both proteins are relatively enriched in Aplysia nervous system, but are also found to a significant degree in other tissues. The expression of mRNA for these proteins in Aplysia nervous tissue is regulated during development, roughly paralleling the reported emergence of several forms of synaptic plasticity. The messages are present at low levels in stage 11, show a large increase by late stage 12, and decline to a plateau of approximately 30% of the peak value afterward. On the basis of the properties of these proteins and by analogy with proposed functions of some of the retinal homologues, we suggest that these proteins may play a role in mediating calcium-dependent processes in neuronal function. The presence of both proteins in other tissues may suggest analogous roles for the proteins in other cell types.

Animals↗
PubMed1996

Factors affecting contrasting results between self-reported and performance-based levels of physical limitation.

We have examined the role of socio-demographic variables, cognitive and affective functioning, and personality in discrepancies between performance-based and self-report measures within three domains of physical limitations: motor functioning, hearing and vision. Data are drawn from a community-based sample of 624 persons of 57 years of age and older. The strength of the association between self-reported and performance-based levels of physical limitations is moderate. Socio-demographic variables and levels of cognitive functioning explained some of the discrepancies between self-reported and performance-based vision. Within the domains of motor functioning and hearing, discrepancies were substantially influenced by affective functioning and personality. The discrepancies may reflect bias in perception or true variation in the effect of limitations on daily functioning. Both self-report and performance-based measures seem to complement each other in providing useful information about physical limitations.

Activities of Daily Living↗
PubMed1996

Long-term persisting cognitive sequelae of traumatic brain injury and the effect of age.

This study examined the notion that mild to moderate traumatic brain injury (TBI) may have persistent effects that become evident upon neurocognitive testing in a phase in which the effects of physiological aging become manifest. Neurocognitive performance was tested in 25 middle-aged and 20 old subjects who had sustained mild to moderate TBI, on average, several decades earlier. The TBI subjects regarded themselves as normal and healthy. The performance of the TBI subjects was inferior to that of matched healthy controls on all aspects of primary and secondary memory and on the majority of tests used to measure speed of performance. There was no interaction between the effects of TBI and those of age, and the performance of middle-aged TBI subjects was similar to that of old controls. The results are taken to indicate that TBI sustained earlier in life may cause permanent sequelae in specific domains of cognitive functioning and that it might attenuate the age-related decline in cognitive functioning. Most striking, however, was that these deficits were not perceived as a limiting factor in everyday life, which suggests that coping strategies may be important.

Adaptation, Psychological↗
PubMed1996

Glycoprotein H of human cytomegalovirus is a major antigen for the neutralizing humoral immune response.

A recombinant baculovirus expressing glycoprotein H (gpUL75) of human cytomegalovirus was used to examine the humoral immune response in naturally infected individuals. Recombinant baculovirus infected insect cells produced two forms of gH with molecular masses of 78-82 kDa and 94 kDa. The 94 kDa polypeptide was modified by high mannose oligosaccharide side-chains as shown by reduction in molecular mass after treatment with endoglycosidases H and F. The 78-82 kDa protein represented the non-glycosylated precursor which was resistant to the enzymes. In contrast to gH expressed in mammalian cells, the recombinant baculovirus expressed gH was transported to the cell surface. Glycoprotein H produced in insect cells was reactive with human convalescent sera and all tested neutralizing monoclonal antibodies recognizing either linear or conformational epitopes. Antibodies reacting with insect cell derived gH were detected in 96 percent of HCMV seropositive human sera. Using insect cells infected with the gH expressing recombinant baculovirus as immunoabsorbent, between 0 percent and 58 percent of the total virus neutralizing activity was removed from sera of individuals with a past HCMV infection. gH must therefore be considered a major antigen for the induction of neutralizing antibodies during natural infection.

Animals↗
PubMed1996

[Pathophysiologic principles and clinical effects of local drug therapy of tubal pregnancies].

OBJECTIVE: An empirically established serum beta human chorionic gonadotropin (beta-HCG) threshold level of 2,500 IU/l is considered as the limit for successful drug therapy. The purpose of our study was to ascertain if this threshold level correlates with the histopathology. Further, we evaluated the effects of local drug therapy on the tubal wall. METHODS: Between 1988 and 1993 129 cases of tubal pregnancies were treated by local prostaglandin F2 alpha instillation. For final cure 30 patients had to undergo further surgical measures. Our study was based upon the histological samples which were excised during secondary operation. RESULTS: Below 2,500 IU/l beta-HCG, intraluminal growth of the trophoblast is more frequent, whereas at higher values extraluminal spread predominates (p = 0.0045). Cells of ectopic trophoblast proliferate significantly slower than those of intrauterine pregnancies. Prostaglandin F2 alpha application selectively destroys ectopic gestational tissue and preserves the tubal wall. CONCLUSION: The integrity of the tubal wall with its contractile potential is essential for successful therapy by local instillation of prostaglandin F2 alpha.

Abortifacient Agents, Nonsteroidal↗
PubMed1996

Cloning, nucleotide sequence, and functional expression of the Escherichia coli enolase (eno) gene in a temperature-sensitive eno mutant strain.

The entire Escherichia coli eno gene was cloned by functional complementation of a newly isolated temperature-sensitive enolase mutant and its nucleotide sequence determined. The deduced amino acid sequence is homologous to other known prokaryotic or eukaryotic enolases and amino acid residues, assumed to be involved in substrate or cofactor binding and catalysis, were found to be strictly conserved among all enolase proteins. Expression of the eno gene under the control of the lac promoter/operator resulted in an IPTG-inducible production of enzymatically active enolase in wild-type and enolase mutant strains.

Amino Acid Sequence↗
PubMed1996

Determinants of loneliness in Jerusalem's 70-year-old population.

This study aims to find the determinants of feelings of loneliness in 70 year olds living in Jerusalem. Results based on home interviews (n = 605) of a 40% systematic sample of 70 year olds in the electoral register showed that around 46.3% of females and 21.3% of males reported being lonely. Persons of European/North American origin felt less lonely than those of Asian or African origin, probably due to the former's wider social support network, perceiving friends, neighbors or other relatives as being available to back up children in an emergency. The major factors associated with loneliness were: being depressed, having a poor self-assessed health status, not attending synagogue, and being widowed but not remarried. Factors that did not reduce loneliness included having paid employment, watching TV or listening to the radio. No association was found between cognitive status and loneliness. Our systems model suggests a strong reciprocal relationship between loneliness and depression.

Aged↗
PubMed1996

Peptide secondary structure mimetics: applications to vaccines and pharmaceuticals.

An important goal of structural biochemistry is the reduction of complex molecules to small functional units that are amenable to high-resolution structural analysis and rapid modification. The dissection of multidomain proteins into small synthetic conformationally restricted components is an important step in the design of low molecular weight nonpeptides that mimic the activity of the native protein. Mimetics of critical functional domains might possess beneficial properties in comparison to the intact proteinaceous species with regard to specificity and therapeutic potential, and are valuable probes for the study of molecular recognition events, and the development of novel vaccines and pharmaceuticals.

Amino Acid Sequence↗
PubMed1996

Outcome after surgical intervention in children with chronic inflammatory bowel disease.

A retrospective review of 32 children and adolescents (18 males and 14 females) with chronic inflammatory bowel disease (CIBD) requiring surgery was undertaken. These patients were followed between 1979 and 1992. Their age range was from 4 to 17 years at the time of diagnosis (mean age, 11 years). The interval between the time of diagnosis and surgery ranged from 2 months to 11 years (mean, 3.7 years). Ten patients had ulcerative colitis and 22 had Crohn's disease. These patients represented 12 per cent of patients with CIBD seen at the Gastroenterology Clinic of Children's Hospital of Michigan during these 13 years. Indications for surgery included failure of medical treatment (seven patients), localized disease with significant side effects of therapy (nine), partial or complete obstruction (five), growth retardation (six), perforation (two), abscess and fistula (three). The extent of disease was as follows: panenteric, 2 patients; enteric, 2 patients; ileocecal, 15 patients; and colonic, 13 patients. In 15 patients (47%) surgery led to complete relief of symptoms for a minimum of 1 year after surgery. Seven patients (22%) had recurrence of symptoms that were controlled by medical treatment. Two patients required a second surgery and additional medical and nutritional treatment. All six patients having surgery for growth retardation showed catch-up growth in weight and height. We conclude that surgery can decrease morbidity and improve quality of life in CIBD patients. Best results are obtained in patients with localized disease.

Adolescent↗
PubMed1996

The Cardiothoracic Outreach Programme--a pilot project.

OBJECTIVE: To test the practicality, safety and benefits of major cardiothoracic surgery in two rural hospitals. DESIGN: Analysis of morbidity and mortality outcomes of a random collection of 35 patients, who underwent diverse surgical procedures. At each visit, the cardiothoracic team of Ga-Rankuwa Hospital-one surgeon, three registrars, two medical officers, six nurses, and four perfusionists-moved all equipment for major surgery, including bypass machines, to two small rural hospitals. Ga-Rankuwa Hospital, as a tertiary hospital attached to a medical school (Medical University of Southern Africa), mounted an outreach programme on a trial basis. The exercise was designed to render assistance, offer decentralised services, and test the skills of the cardiothoracic team in an environment where high-technology procedures have never been undertaken by the local health professionals. SETTING: Two rural hospitals, viz. Tintswalo and Mankweng, in the referral area of MEDUNSA, with no conventional ICU facilities. The support services for operative, pre-operative and postoperative care were very basic. The local personnel consisted only of general nurses and medical officers. None had experience of high-technology or complex theatre work. PARTICIPANTS: Thirty-five randomly selected patients of both sexes with ages ranging from 11 years to 64 years. Pre-operative diagnoses of diverse cardiac and lung conditions were made. The operations performed comprised 35 major procedures, including open heart operations and major lung procedures. The personnel comprised the MEDUNSA cardiothoracic team, who were assisted by local nurses. INTERVENTION AND OUTCOME: Thirty-five patients underwent 35 major procedures, all under general anaesthesia. Twenty cardiopulmonary bypasses were performed. There was 1 intra-operative death, due to low-output state. Intra-operative morbidity occurred in 2 of the 35 operations. These consisted of a cerebrovascular accident (CVA) (air embolism), and a temporary heart block. Late outcomes (after 1 week) were also analysed; the incidence was 1/35 operations. This was a CVA due to a left atrial appendage clot. Staff morale at the local hospital improved remarkably. The process of teaching the local professional nurses was surprisingly easy. Benefits included a decreased referral rate (100%), lower costs (transport, medicines, operations), excellent patient and community confidence in the work of the hospitals (increased hospital outpatient numbers), and political support (new tools, upgraded facilities and new equipment). RESULTS: The exercise was a resounding success in both measurable and general terms. All operations were successfully performed, with very low adverse outcomes (morbidity, mortality) and good quality of life for all the subjects. The safety and cost-effectiveness of cardiothoracic surgery under primitive conditions were demonstrated. The standard of patient care improved, and local staff acquired good basic skills in patient care. The referral patterns changed for the better and the confidence of the community in the services was enhanced. The risk/benefit ratio of the exercise was commendable. The feasibility of an extended service was encouraging.

Academic Medical Centers↗