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Biomedical subjects

G May

Publications and source records attributed to G May.

At least 109 records · Page 6Linked to original sources

An evolutionary comparison of homologous mitochondrial plasmid DNAs from three Neurospora species.

We have discovered a mitochondrial DNA plasmid in N. crassa 516 (Roanoke, LA) which is homologous to those previously described from N. intermedia 435 (Fiji) and N. tetrasperma 2510 (Hanalei, HA). Subsequent analysis by DNA-DNA hybridization showed that 6 of 14 other Louisiana N. crassa isolates possessed plasmids homologous to these three plasmids, but at lower copy number. Plasmids from the three named strains were studied to examine possible plasmid diversity within each isolate, the extent of the homology between the plasmids, and the possibility that these plasmids could be inherited separately from their host mitochondria. Comparison of cloned plasmids and covalently closed circular mitochondrial DNA showed that only one plasmid line was present in each of the three intensively studied isolates. DNA-DNA hybridization and restriction endonuclease site mapping showed that the mitochondrial plasmids from the three species were very similar; most of the variation was due to presumed nucleotide substitutions. Plasmids judged identical by our analysis were found in different species. The distribution of the homologous plasmids in nature and the presence of these identical plasmids in different species, suggested that these plasmids could be transmitted between isolates independently of their host mitochondria.

Biological Evolution↗

The etiology and treatment of delayed bleeding following percutaneous lithotripsy.

In 1,032 percutaneous stone manipulations the incidence of significant, documented or presumed vascular injuries was 0.9 per cent. Seven cases of pseudoaneurysm, arteriovenous fistula or vascular lacerations were found, all of which were diagnosed angiographically. The patients were treated successfully with transcatheter embolization techniques. Two additional patients experienced delayed bleeding, presumably from vascular injuries, which resolved spontaneously with conservative therapy. Arteriography should be performed in these patients with serious postoperative bleeding. Embolization of the peripheral vessel is preferable to flank exploration.

Aged↗

[incidence of cytomegalovirus infections following transplantation of kidneys from seropositive and seronegative donors].

Serum samples of 110 recipients of kidney transplants and the 100 donors belonging to them taken before the transplantation were examined for complement-binding antibodies against cytomegaloviruses. A clear influence of the cytomegalovirus antibody state of donor and recipient on the cytomegalovirus infection appearing after transplantation, serologically ascertained by cytomegalovirus-IgM-antibody proof or seroconversion and fourfold increase of the titre in the complement-binding reaction, respectively, could be made evident. Cytomegalovirus negative recipients of kidneys of cytomegalovirus positive donors had significantly more infections than seronegative recipients of kidneys of seronegative donors (50% vs. 16%, p less than 0.05). According to the infection rate the seropositive recipients stand with about 30% between these two groups. It seems that in these recipients the serological state of the donors has no influence. These findings make evident that seronegative recipients receive the cytomegaloviruses essentially with the transplant, whereas the cytomegalovirus infections in seropositive recipients are endogenous cytomegalovirus reactivations caused by therapy.

Adolescent↗

[Frequency of infection with cytomegaloviruses (CMV) following kidney transplantation and initial experiences with CMV gamma globulin prevention].

In a retrospective study we investigated 364 patients who had received cadaveric kidney transplants between 1978 and 1984 as to cytomegalovirus (CMV) infections using complement-fixation test and indirect immunofluorescent test (IgM, IgG). Before transplantation, 194/364 patients were seropositive and 170/364 were seronegative. After transplantation, seroconversion or an increase in titre (greater than or equal to 4 fold) was found in 26% of seropositive recipients and in 30% of seronegative recipients. In contrast to the secondary infections (approximately 40% asymptomatic or oligosymptomatic), the primary infections were regularly connected with a clinical symptomatology. As to the recipient's and donor's pre-transplant antibody status the highest infection rate (62%) was seen in the group of seronegative recipients of kidneys from seropositive donors. Preformed CMV antibodies seem to be useful in preventing severe CMV-diseases. Therefore, in April 1985 we started a randomized study in order to investigate the efficacy of an i.v. cytomegalovirus-immunoglobulin (CMV-Polyglobin/Cutter). There were no side effects. Already 4 h after infusion we were able to detect CMV-IgG-antibodies (IFT) in peripheral blood. This passive immunization, however, was not capable to prevent a CMV infection in each case; there were 5/8 seroconversions and 4/8 symptomatic CMV infections. Nevertheless, we think the application of CMV immunoglobulin has a beneficial effect.

Antibodies, Viral↗

Neuroendocrine effects of apomorphine in chronic schizophrenic patients under long-term neuroleptic therapy and after drug withdrawal: relations to psychopathology and tardive dyskinesia.

The sensitivity of the dopaminergic hypothalamic pituitary system, as indicated by growth hormone (GH) release after apomorphine (0.5 mg SC), was studied in 11 chronic schizophrenic in-patients under long-term neuroleptic (NL) therapy and after 12 and 30 days' drug withdrawal. GH peak levels after a 12-day drug-free period were significantly elevated (13.1 +/- 12 ng/ml) as compared to NL therapy (4.6 +/- 6.1 ng/ml). Controls showed a significant higher mean peak GH response (13.6 +/- 10 ng/ml) compared to chronic schizophrenic patients under long-term NL therapy. The GH response of patients with symptoms of tardive dyskinesia (TD) did not differ significantly from that of patients without signs of TD. The prolactin (PRL) serum levels under long-term NL treatment were within the normal range in male schizophrenics but decreased significantly after 12 days' drug withdrawal. The data presented indicate a reduced sensitivity of the hypothalamic-pituitary dopamine receptors under long-term NL therapy. The significant increase in GH response on day 12 probably corresponds to a readjustment from a mostly blunted GH response under NL therapy back to stimulated levels of normal controls. No supersensitivity of the pituitary dopamine receptors could be detected.

Adult↗

Distribution and evolutionary significance of mitochondrial plasmids in Neurospora spp.

A mitochondrial plasmid line in the fungal genus Neurospora is geographically widely distributed and occurs in isolates of at least two species. On the basis of characterization with restriction endonucleases, it is apparent that plasmids from isolates of Neurospora tetrasperma are more closely related to one another than to an evolutionarily homologous plasmid from Neurospora intermedia; N. tetrasperma plasmids from Surinam and Hawaii differed from one another only slightly by our analysis, whereas the plasmid from N. intermedia (Fiji) exhibited substantial restriction site divergence from all N. tetrasperma plasmids. We believe these observations strengthen the presumption that four-spored isolates of Neurospora spp. represent a natural taxonomic grouping (N. tetrasperma). The plasmids from N. tetrasperma and N. intermedia (Fiji), although clearly related to each other as shown by hybridization studies, exhibited no detectable homology with either of two additional plasmid lines from isolates of Neurospora spp. Nor did they exhibit homology with the mitochondrial genome. Despite this lack of homology among three distinct plasmid lines, all the plasmids may possess a common mode of replication.

Biological Evolution↗

[Fc IgG carrying T lymphocytes in healthy adults and patients following kidney transplantation].

In 28 healthy adults aged 19 to 52 years, normal values of the TG lymphocytes amount to 17.8 +/- 2.3% and 253.1 +/- 96.1 per microliters respectively and the non TG/TG ratio to 4.72 +/- 0.82. When compared with normal controls, patients on dialysis had a disturbed non TG/TG ratio (4.72 +/- 0.82 vs. 6.00 +/- 1.94, p less than 0.05). During the first posttransplant month the total TG cell count was significantly reduced, but the relative TG cell count did not significantly differ from the normal as well as praeoperative TG cell count. In connection with rejection crises we could not observe any changes in the TG subset. Beside this general dynamics we observed two different kinds of changes of the non TG/TG ratio in the individual posttransplant course. Either the non TG/TG ratio were lower than praetransplant or higher. In 9 out of 9 cases the lowering of the non TG/TG ratio (that means a relative or absolute increase of Fc-IgG receptor bearing T cells) were connected with a good graft function. In 4 out of 6 cases a postoperative increase of the non TG/TG ratio were connected with an early graft failure. A change of T subsets for the benefit of TG cells which includes suppressor cells seems to be favourable with regard to the graft survival. Therefore, we think the determination of the prae- and posttransplant non TG/TG ratio is of some prognostic value.

Adult↗

[Effect of plasmapheresis treatment on immunoglobulin and immune complex levels in patients following kidney transplantation].

Five patients who received cadaver kidneys between May 1982 and January 1983 in the Kidney Transplant Centre in Berlin were subjected to two plasmapheresis (= pph.) treatments in addition to basic immunosuppression with Prednisolone and Azathioprine. The decision to use pph. was due to the presence of donor-specific, complement-dependent lymphocytotoxic antibodies (51Cr release test) in the recipient's serum taken immediately before transplantation. The 1st pph. was carried out on the 1st or 2nd day after operation and the 2nd pph. between the 2nd and 4th day. The quantity of plasma exchanged was between 1.6 and 3.1 1 per pph. Four of the five transplants commenced functioning after 12 to 47 days, and one transplant had to be removed. Frequent measurement of the immunoglobulin and immune-complex levels in the serum revealed drastic reduction due to pph. The concentration of immunoglobulin (G, A, M) was reduced by 42-55% after the 1st pph. and by 20-35% after the 2nd. Whereas the IgM level was normalized after a few days, the levels of IgG and IgA only rose again 2-4 weeks later. The immunodeficiency induced by means of pph. and immunosuppression is accompanied by an increased risk of infection. It is therefore considered important that an adequate anti-infectious treatment including i. v. human gammaglobulin be administered parallel to pph. The final evaluation of the efficacy of pph. in protecting transplants will depend on further studies.

Adolescent↗

[Anti-Thomsen-Friedenreich (anti-T) antibody titer in kidney transplant recipients].

In 43 recipients of allogenic cadaver kidneys before and three times a week after transplantation to the discharge from the hospital care the antibody titre against the Thomsen-Friedenreich-antigen (Anti-T) was determined and the score value was calculated from the agglutination intensity. A prognostic significance of the value got before operation could not be found. No changes of the titre appeared under the influence of the postoperatively performed immunosuppression as well as in connection with rejection crises. In 9 patients with clinically manifest systemic infections (8 cytomegalovirus infections, 1 bacterial infection) unequivocal (greater than or equal to 8 fold) increases of the anti-T-titre could be proved. These findings speak for an infection-induced formation of these cross-reacting anti-T-antibodies.

Adolescent↗

[Urinary enzyme excretion in kidney transplant patients].

In a survey the present state of the activity determination of urinary enzymes after kidney transplantation as a diagnostic tool in the control of patients with transplanted kidney is described. A great number of enzymes has up to now been established in these patients. The most extensive data are present for the enzymes alanine-aminopeptidase, N-acetyl-beta-D-glucosaminidase and lysozyme. After the transplantation of the kidney typical excretion patterns of the enzymes in the urine are observed in immediate function, retarded onset of the function, without function and acute rejection of the graft. Particularly the behaviour of the urinary enzyme excretion during acute rejection reactions can be diagnostically used. Hereby, the diagnostic reliability of determinations of the activity of urinary enzymes is, however, differently assessed by various authors. In future works in close cooperation between clinic and laboratory the diagnostic validity of the determinations shall unambiguously be characterized and the determinations of the enzyme activity in the urine should be summarized together with other parameters to an optimum combination of parameters for the follow-up investigation of patients who underwent kidney transplantation.

Acetylglucosaminidase↗

Microvascular surgery in experimental and clinical kidney transplantation.

An improved microsurgical technique for orthotopic rat kidney transplantation is described in detail. (1) End-to-end anastomosis of renal arteries with 7-8 interrupted 10-0 sutures. (2) End-to-end anastomosis of renal veins with 2 continuous semicircular 10-0 sutures. (3) Non-splinted end-to-end ureteric anastomosis with 4 interrupted full-thickness 11-0 sutures. (4) Simultaneous bilateral nephrectomy. Seventy transplantations were analysed. No failure due to complications of the vascular anastomoses occurred. The ureteric anastomoses were complicated by stenosis in only 5 animals (7%). The operation times for vascular anastomoses were 20 (15-24) minutes and for complete transplantation 50 (45-60) minutes. This technique seems to be less time consuming than other methods. Our method has produced a success rate of 93% with well standardized and reproducible organ quality. Preliminary clinical experiences with extracorporeal microvascular reconstruction in 4 cases of injured small polar kidney allograft arteries support the continued application in appropriate situations to increase the number of suitable donor kidneys.

Animals↗

Changes in body size and fatness of Australian schoolchildren 1911-1976.

Data have been analysed from surveys of Queensland schoolchildren done in 1911, 1950 and 1976. Over this period there has been a marked increase in both height-for-age and weight-for-age in boys and girls. However, in boys, this increases growth has been associated with minimal increase in fatness. In girls there has probably been a real increase in body fatness, particularly since 1950. Raw data from past growth studies would make the analysis for secular changes in status more meaningful and accurate. We suggest that a central data bank for Australian growth studies be set up.

Adipose Tissue↗

[Primary cytomegalovirus infection as a risk factor following kidney transplantation].

Of 201 patients who received cadaver kidneys in the kidney transplant centre in Berlin between June 1978 and December 1981 114 (56.7%) already had complement-binding antibodies against cytomegaloviruses (CMV) before transplantation, 87 (43.3% were seronegative. After transplantation a recurring CMV infection was detected in 36/114 patients and a primary CMV infection in 27/87 patients (31.6% and 31.0% respectively). At dismissal from ward care these patients already had a significantly higher rate of transplant failure than those free of CMV infection. This negative effect of the infection was reinforced by the additional administration of a Prednisolone bolus for the treatment of the rejection crisis associated with CMV. At the same time immunological protection was further suppressed. Thus, in comparison with patients with primary CMV infection not treated with Prednisolone bolus, those with primary CMV infection and parallel treatment with a Prednisolone bolus had a higher rate of T-lymphocytopenia and a significantly delayed humoral immune response to CMV. Together with the usually present leukocytopenia, these findings explain the especially high risk of potentially fatal superinfections in this period. Diagnosis of CMV infection on the basis of clinical symptoms and haematological changes must be speedy. A therapy which is effective with regard to life (although symptomatic) comprises the temporary reduction of the azathioprine dose, the administration of antibiotics and the infusion of human gamma-globulin. It might be possible to avoid primary CMV infection, which presents a particularly great risk, by vaccination of the potential transplant recipient.

Adolescent↗

[Pregnancy after kidney transplantation. Report of 6 successful cases with multiple risk factors].

The long-term course before, during and after successful pregnancy in six women 3 to 6 years after receiving CD-kidney transplants from dead donors is described. Multiple risk factors such as hypertension, considerable proteinuria, preceding rejection crises etc. have been taken into account. The analysis includes the observation of a pregnancy which began already in the 1st month after transplantation. With the exception of a patient with hydronephrosis, whose functional data remained normal, the transplants of all patients showed better functional data after delivery than before pregnancy (maximum period of observation: 5 years 3 months post delivery). The patients mainly received alternating prednisolone therapy. Immunosuppression was generally reduced in the second trimester and was temporarily increased above the maintenance dosage after delivery. All children were eutrophic at birth and developed normally without complications. Important factors leading to the good overall clinical result were intensive out-patient care and the cooperation between nephrologists, urologists, gynecologists and neonatalogists. Despite our very good experience with 6 pregnancies successfully carried to full term by women with kidney transplants, the risk for mother and child should only cautiously be estimated, taking into account the results of future larger studies.

Adolescent↗

Tetrachlorodibenzodioxin: a survey of subjects ten years after exposure.

Ten years after an incident following which 79 workers developed chloracne due to exposure to tetrachlorodibenzodioxin a study was undertaken to establish the current state of health of the affected employees remaining in the company's (Coalite Oils and Chemicals Ltd, a subsidiary company of Coalite Group Ltd) employment. The opportunity was used to examine effects on mortality, morbidity, carcinogenesis, reproduction, teratogenicity, fetotoxicity, biochemistry, immunology, and genetic change. Concurrently, control groups were established with which to make comparison. The control groups selected from within the works matched the study group in respect of sex and age but it was not possible to match them for occupation and social status. Half the affected subjects still have minor chloracne. Other than this there is no evidence that they have been adversely affected in any way.

Abortion, Spontaneous↗