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Biomedical subjects

M Klein

Publications and source records attributed to M Klein.

At least 595 records · Page 33Linked to original sources

Canadian departments of pediatrics and family medicine: in need of family therapy?

Whether and how much the departments of pediatrics in Canadian medical schools collaborate with the family medicine departments in training for child care were the focus of a survey conducted in 1983-84. Responses to a questionnaire sent to department heads indicated that in general the most supportive relationships existed in the western provinces, with progressively more problems uncovered from west to east. The responses concerning the roles of pediatricians and family physicians paralleled this trend, with the western view being that pediatricians are consultants and not competitors for primary care. Many respondents supported the expansion of family medicine, particularly into ambulatory and behavioural areas. The data provide some cause for concern about the future health care of children, as the forecasted oversupply of physicians is likely to encourage competition rather than consultation between the two groups. Also, many Canadian pediatricians accept the US model of pediatrics, which includes primary care, although in Canada the ratio of family physicians to pediatricians is six times that in the United States, and Canadian specialists are concentrated in urban centres. This means that family physicians will continue to provide most of the child care in Canada and need adequate training. They also need to develop cooperative, supportive relationships with specialists in child health care to enhance appropriate referral patterns.

Canada↗

Pharmacological and neurochemical aspects of kindling.

Rats implanted with amygdaloid stimulating and cortical recording electrodes were kindled by daily low-intensity electrical stimulation. In one experiment amino acid concentrations were measured in amygdala, cortex and hippocampus at behavioural stages 1, 2 and 4 (Racine). Control groups consisted of unstimulated rats. Only alanine showed a significant enhancement of concentration in the kindled rats (stage 4 of Racine). In a second experiment, a group of rats was treated daily with 10mg/kg p.o. of diazepam. Diazepam significantly inhibited kindling and no changes in amino acid concentrations were observed in this group. Increased alanine levels are seen after various seizure types; since pentetrazole, isoniazid and beta-vinyllactic acid seizures were associated with alanine level increases only after and never before seizure occurrence, it is suggested that the alanine increases are a consequence rather than a cause of convulsions. In 3H-flunitrazepam binding studies, no change in affinity or receptor number could be demonstrated during kindling.

Alanine↗

The specific protective effect of diazepam and valproate against isoniazid-induced seizures is not correlated with increased GABA levels.

Amino acid concentrations were measured in the cortex, cerebellum and hippocampus of the mouse brain before and during seizures induced by isoniazid (250 mg/kg i.p.), an inhibitor of L-glutamate-1-decarboxylase (EC 4.1.1.15: GAD). Valproate sodium and diazepam dose-dependently delay the onset of convulsive fits caused by isoniazid. However, neither diazepam nor valproate prevented the decrease in GABA concentrations produced by isoniazid alone. Also, these antiepileptic drugs did not modify the rate of GABA depletion elicited by isoniazid. These results, observed in four different brain structures, strengthen those first obtained with beta-vinyllactic acid, another inhibitor of GAD.

Amino Acids↗

Expression of a monocyte-specific esterase isoenzyme in cases of acute myeloid leukemias.

The carboxylic esterase (E.C. 3.1.1.1) isoenzymes from cases of acute myeloid leukemias were separated by analytical isoelectric focusing on horizontal thin-layer gels. One isoenzyme consisting of one or two components (bands) could be completely and selectively inhibited by addition of 40 mM sodium fluoride (NaF) to the staining bath. The 105 cases were classified into the groups M1-M6 according to the FAB proposals. The NaF-sensitive isoenzyme was not detected in cases of FAB groups M1/2 (acute myeloblastic leukemia without or with maturation), group M3 (acute promyelocytic leukemia) or group M6 (erythroleukemia). Thirty-one out of 33 cases in the FAB group M4 (acute myelomonocytic leukemia) and 9/9 cases in FAB group M5 (acute monocytic leukemia) expressed the NaF-sensitive isoenzyme. The NaF-sensitive isoenzyme was found at different staining intensities; all M5 cases showed the isoenzyme at strong or very strong intensity, whereas most of the M4 cases displayed the isoenzyme at weak, medium or strong staining intensity. The data presented are further evidence that the presence of the NaF-sensitive esterase isoenzyme indicates monocytic involvement or differentiation in cases of myeloid leukemias. The easy and fast to perform method of isoelectric focusing can be used to distinguish the monocytic variants among the acute myeloid leukemias and can supplement the morphological analysis of these cases.

Carboxylic Ester Hydrolases↗

Autofluorescence of alveolar macrophages: problems and potential solutions.

Despite recent advances in immunofluorescence technology, the study of alveolar macrophage cell surface proteins is hampered by the presence of autofluorescence. We suggest several approaches that might overcome this problem and enable specific immunofluorescent detection of cellular proteins and automated analysis of alveolar macrophages.

Cytophotometry↗

[Naftidrofuryl in the treatment of simple diabetic retinopathy. A double-blind study].

During a randomized double-blind study 23 patients with nonproliferative diabetic retinopathy were treated orally with 600 mg Naftidrofuryl daily for six months, while 25 patients served as control group. Measurements of visual acuity and fundus photography were performed before and after 3 and 6 months of observation. Measurement of visual acuity showed a significant deterioration in the functional state of eyes in the control group. This deterioration was clearly less pronounced in the treated group, though not statistically significant. There was no significant change in the amount of exudation in either group. In contrast, retinal bleeding and the number of microaneurysms increased significantly both within the control group as well as compared with the treated group (p less than 0.05). This progression was checked to a significant extent in the treated group. Thus, the overall assessment of therapy indicated that Naftidrofuryl treatment brought significant advantages (p less than 0.05).

Aged↗

Similarity of pituitary and pineal human oxytocin neurophysins indicated by peptide mapping after radioactive alkylation and proteolysis.

We have compared the immunoreactive oxytocin neurophysin from the human pineal gland with human neurohypophyseal neurophysin. The two proteins were reduced and carboxymethylated with [14C]-iodoacetic acid. Since the pineal protein was available only in a very small amount, we were obliged to use [12C]-carboxymethyl apomyoglobin as a nonalkylatable carrier. The trypsin and subtilisin digests of the two labelled proteins were compared by high-voltage electrophoresis on paper, partition paper chromatography, and high-performance liquid chromatography. The distribution of radioactivity in the above peptide separations suggests a great similarity between the two proteins and few significant differences. As far as we are aware, this study is the first attempt to analyze an extrahypophyseal neurophysin at the molecular level.

Alkylation↗

Evaluation of clinical and prognostic significance of T cell regulatory subsets in rheumatoid arthritis.

Phenotypic analysis of circulating lymphocytes and T cell subsets using monoclonal antibodies was performed on 60 patients with rheumatoid arthritis (RA). A significant lymphopenia was observed in RA patients and correlated with the use of disease suppressant drugs (p less than 0.0001). A significant decrease in the number of suppressor/cytotoxic T cells resulted in an increase in the TH/TS ratio in 40% of RA patients. This elevated ratio did not correlate with disease activity, the presence of extraarticular features, autoantibody production or immune complex formation. We conclude that the evaluation of the TH/TS ratio has no diagnostic or prognostic value.

Arthritis, Rheumatoid↗

Noncovalent association of heavy and light chains of human immunoglobulins. IV. The roles of the CH1 and CL domains in idiotypic expression.

A rabbit anti-idiotypic antiserum was raised against a monoclonal human IgM kappa(Me) in order to analyze the possible modulation of idiotypic expression by Fab constant domains. IgM(Me) fragments, subunits, and domains were prepared by chemical and enzymatic cleavages. All molecular species were shown to have a well-defined secondary and tertiary structure by circular dichroism. Full recombination between domains and subunits was ascertained by difference spectroscopy. The expression of the idiotype on native and recombined fragments, domains, and subunits was quantitated in a competitive enzyme-linked immunosorbent assay (ELISA). Reduced and alkylated Fab, isolated H and L chains, purified Fv(Me), intact VH and VL domains and H-L, VH-L, VL-H, and VH-VL recombinants were compared on a molar basis to native Fab(Me) for idiotypic expression. VH-specific determinants were found, whereas the L chains were virtually devoid of idiotypic activity. Both the peptic FV(Me) fragment, which is composed of intact VH and VL domains, and the recombined VH-VL heterodimer were found to be fourfold less active for idiotype expression than native Fab(Me). However, full inhibition was achieved at high molar concentrations, suggesting that all the idiotopes present on Fab(Me) were expressed on FV(Me) but with a reduced antigenicity. Comparison of VH-L and VL-H hybrid molecules revealed that the presence of the C mu 1 domain was sufficient to restore full idiotypic expression as compared with native Fab(Me). These data support the hypothesis that the first constant domain of the mu heavy chain alters the quaternary interaction between the variable domains, and therefore modulates the expression of the idiotype through longitudinal interactions that are not affected by reduction of the inter-H-L chain disulfide bond.

Antibodies, Anti-Idiotypic↗

[Toton, a new total prosthesis for replacement of the ossicle chain].

After 4 years of use a new total prosthesis is proposed for replacement of the auditory ossicles, that is perfectly biocompatible since it is composed partly of the fresh autologous cartilage, which will be in contact with the drum and partly of teflon, which will be in contact with the foot of stapes. Results of a study in 44 patients, with follow up of more than 4 years in some cases, have shown: recovery of from 50 to 91% of audition in 61% and from 30 to 49% in 25% of cases, and lack of recovery in 13%. The Toton should resolve the problem of biocompatibility, a very controversial subject, and provide a solution to functional rehabilitation of empty cavities.

Bioprosthesis↗

[Presentation and trial of a new medium-duration transtympanic ventilator].

A new transtympanic aerator for medium duration of use and made of flexible silicone is presented, its funnel shape preventing stagnation of plugs or allowing their simple removal. The cavity mucosa remains visible and the installation of medication is facilitated. A statistical analysis of results in 159 cases showed that it remained in place for 9 months in children and 7 months in adults on average. A total of 310 conical drains have been inserted since 1981, without any incident because they are extremely well tolerated.

Adult↗

Nondomestic mammalian bites.

Life-threatening injuries resulting from wild animal bites are always treated first. Local wound management varies, depending on the type of wound and its location, but scrupulous cleansing and copious irrigation are mandatory. Tetanus prophylaxis and rabies prophylaxis are provided according to accepted guidelines. Antibiotic prophylaxis is not routinely necessary but is advisable for wounds of the hands or joints and for wounds in immunocompromised individuals.

Adult↗

Care in a birth room versus a conventional setting: a controlled trial.

A controlled clinical trial was carried out to assess whether a birth room setting would influence the care of mothers and newborns. Of the 163 low-risk women enrolled, 49 (30%) manifested some prenatal risk and were excluded. The remaining 114 were allocated by strict alternation to a birth room or a conventional setting. Of the 56 women allocated to the birth room, 63% of the primiparas and 19% of the multiparas were later transferred. The numbers in the two settings who had oxytocin stimulation, epidural anesthesia, forceps delivery or cesarean section did not show statistically significant differences. The episiotomy rates were slightly lower in the birth room than in the conventional setting, and the rates of an intact perineum were higher in the birth room. Neither the Apgar scores nor the morbidity rates of the infants showed statistically significant differences related to the setting to which the mother had been allocated, although more infants from the conventional setting were admitted to a special care unit. Both "experimental" groups of women less often received routine perineal shaving, enemas or intravenous infusions than did an obstetrically similar nonexperimental comparison group. Despite the apparent inability in this setting for the birth room to influence the rate of major obstetric procedures (except for episiotomy) and outcomes, the authors believe that a birth room is desirable in tertiary care centres as well as in community hospitals.

Adult↗