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Biomedical subjects

C Marks

Publications and source records attributed to C Marks.

At least 55 records · Page 3Linked to original sources
PubMed1983

Extracranial carotid artery injury. Current surgical management.

Fifty patients were treated for extracranial carotid artery trauma during the period from 1954 through 1981. The overall mortality rate was 20 percent. Primary repair was achieved in 38 patients (76 percent) with a mortality of 7.8 percent, and ligation was performed in six patients (12 percent) with a 50 percent mortality. The left carotid system was injured more frequently than the right; hemorrhage from an isolated carotid injury was readily controlled by digital pressure. Associated injuries affected the prognosis adversely. Significant neurologic deficits were present in 12 patients on first admission but the presence of neurologic deficit or coma did not serve as a contraindication to arterial repair and restoration of cerebrovascular continuity. Arteriography was not utilized once the clinical diagnosis of carotid arterial injury was made, but it was utilized when the proximity of the cervical injury provided the only suggestive evidence that vascular damage may have occurred. The presence of significant shock, coma, or neurologic deficit represent adverse prognostic features but do not contraindicate carotid repair. Profuse bleeding from a carotid injury or the presence of severe posthemorrhagic shock require urgent surgery. If control of bleeding is difficult to achieve, then ligation is preferred to suture repair.

Adolescent↗
PubMed1983

Thermostable erythrocyte rosettes in chronic renal failure and allograft rejection.

Rejection of an allograft usually is preceded by activation of T lymphocytes, in which state such cells may be identified by their ability to form thermostable rosettes with sheep erythrocytes (TE-R). The objective of the present work, therefore, was to determine whether or not enumeration of TE-R in the peripheral blood was of any value in the diagnosis of rejection. The results showed no significant differences between TE-R (mean +/- SEM) in normal subjects (9.9 +/- 1.3; n = 25), renal allograft recipients without rejections (13.5 +/- 1.7; n = 5) and in patients who suffered from acute tubular necrosis in the posttransplant period (12.4 +/- 2.5; n = 8). In contrast, recipients who had rejection episodes showed a marked rise in TE-R levels (43.0 +/- 4.0; n = 11) about two to seven days prior to the diagnosis of rejection by clinical and chemical criteria. Furthermore, TE-R remained high if the rejection episodes turned out to be irreversible after therapy (42.2 +/- 3.7) but fell if the episodes were reversible (19.9 +/- 3.2). TE-R values were elevated in patients with chronic renal failure on maintenance hemodialysis (45.7 +/- 4.9; n = 23). Neither acute dialytic runs or acute infections altered TE-R values. In conclusion, those results show that enumeration of TE-R may be helpful in the early diagnosis of allograft rejection, before clinical and chemical stigmata are apparent.

Erythrocytes↗
PubMed1983

Immunobiological determinants in organ transplantation.

The most important development in determining successful organ transplantation has been the improved understanding of the immune response and the interactions between antigens, antibody, immune complexes, complement component, lymphocytes and macrophages. The initiation and termination of an immune response, whether cellular or humoral depends upon cellular interaction between subsets of the lymphocyte cell series and macrophages. An equilibrium between helper and suppressor T cells determines protection of the host from non-self tissue invasion, infection and neoplasia. The role of mediators, immunosuppressants, hybridomas and recombitant DNA technology are briefly considered. The relative importance of tissue typing and blood transfusion in preventing allograft rejection is considered and the role of immunological monitoring in allograft transplantation is reviewed.

B-Lymphocytes↗
PubMed1982

Asymmetric release of estrone and estradiol derived from labeled precursors in perfused human placentas.

Human placentas were perfused in vitro through fetal vessels of a single cotyledon with a solution of tritiated androstenedione (A) or tritiated testosterone in oxygenated Krebs-Ringer bicarbonate buffer containing glucose. The same buffer, without labeled steroids, was used to perfuse the maternal side of the placenta. Fractions of unrecycled "fetal" and "maternal" perfusates were collected to estimate the steady-state rates of output into each perfusate of labeled estrone (E1) and estradiol (E2), formed by aromatization of the perfused androgens. An unequal distribution of the two estrogens was observed, i.e., a significantly larger proportion of E2 than of E1 was released to the maternal perfusate. Addition of unlabeled A or ethinyl estradiol (10(-5)M) to the fetal perfusion buffer resulted in a redistribution of the E2 output toward the fetal perfusate. These in vitro results are similar to the findings of Walsh and McCarthy, who detected by tracer experiments an unequality in the in vivo fetomaternal distribution of the output of placentally produced E1 and E2 in rhesus monkeys. These results also support the possibility of the existence of saturable specific E2 carriers in the syncytiotrophoblast, postulated by the same authors to explain their findings. However, an extrasyncytial conversion of E2 to E1 could also account for the disproportion in the relative output of the estrogens toward mother and fetus. The perfusion system used in these studies may be useful for the elucidation of factors determining the relative rates of placental secretion of steroids toward mother and fetus.

Androstenedione↗
PubMed1982

Current management of paragangliomas.

Since 1948, 33 paragangliomas in 32 patients were seen and studied at Charity Hospital. Tumors of the head and neck comprised the bulk of recorded instances, with only five paragangliomas being noted below the diaphragm. The most frequent symptoms correlated closely with tumor location and were related to local mass effect. Angiography remains an important diagnostic study for tumors of the head and neck with computed tomography scanning becoming increasingly important in large paragangliomas of the jugular region. Paragangliomas of the retroperitoneal space can be successfully located by a computed tomography scan, although a new radionuclide scan may prove to be more specific in the future. Tumors of the urinary bladder and retroperitoneal space are commonly endocrine functional and have a greater metastatic potential than do paragangliomas in other locations. Over-all, total excision is possible with complete recovery in most instances. Prolonged follow-up study is recommended, however, as local recurrences and distant metastases may present years after the initial diagnosis.

Adult↗
PubMed1981

Influence of endometrial 17 beta-hydroxysteroid dehydrogenase activity on the binding of estradiol to receptors.

Specimens of proliferative and secretory endometrium which differ in the levels of 17 beta-estradiol dehydrogenase activity, were superfused with mixtures of [3H]estradiol ([3H]E2) and [3H]ethynyl estradiol ([3H]EE) in the presence and absence of diethylstilbestrol. Concentrations of labeled E2, EE, and estrone were measured in homogenates and in nuclei isolated from the superfused tissues. The relative proportions of [3H]EE and [3H]E2 bound to nuclear receptor were much higher in secretory than in proliferative endometrium. Since EE binds to the estrogen receptor but is not a substrate for 17 beta-estradiol dehydrogenase, these results demonstrate the influence of metabolism on the binding of E2 to the receptor. The elevated enzymatic activity present in secretory endometrium also accounts for the relatively lower concentration of [3H]E2 and the increased [3H]estrone to [3H]E2 ratio in the superfused tissue.

17-Hydroxysteroid Dehydrogenases↗
PubMed1980

Predictive value of serum complement (C3) in renal allograft rejection.

The purpose of this study was to investigate whether or not changes in serum concentrations of complement component C3 are of value in predicting the long term survival of the transplanted kidney. C3 was quantitated by radial immunodiffusion in fresh sera drawn immediately before transplantation and twice weekly thereafter from 10 recipients. Fourteen episodes of acute rejection occurred during the first 3 months postoperatively. These were diagnosed by the demonstration of graft tenderness, fever without evidence of infection and a rise in serum creatinine of 1 mg/dl in the absence of urinary or vascular obstruction. Five rejection episodes in 3 patients were associated with a fall in C3. In one of these patients, C3 returned to normal levels after the episode was reversed, and the kidney is functioning well 2 years after transplantation. In the other 2 patients, C3 remained at low levels regardless of anti-rejection therapy. Transplant nephrectomy was soon required for irreversible rejection. In contrast, only 1 episode unaccompanied by a fall in C3 was irreversible. Evidence is provided concerning the value of serial C3 complement determinations as a predictor of rejection in renal allografts. Using the variability measure Si, the cumulated standard deviation up to week i, Si > 10 not only predicts rejection but does so rather early, providing more than 90 per cent of the ideal lead time. This suggests that loss of a graft may be predicted, but this needs confirmation in additional cases.

Complement C3↗
PubMed1980

The sodium effect of Bacillus subtilis growth on aspartate.

aspH mutants of Bacillus subtilis have a constitutive aspartase activity and grow well on aspartate as sole carbon source. aspH aspT mutants, which are deficient in high affinity aspartate transport as a result of the aspT mutation, grow as well as aspH mutants in medium containing high concentrations of aspartate and Na+. This Na+ effect is not due to an enhancement of aspartate transport but is the result of increased cellular metabolism. The ability to grow rapidly in sodium aspartate is induced by prior growth in the presence of Na+. In potassium aspartate, the addition of arginine, citrulline, ornithine, delta 1-pyrroline-5-carboxylase or proline instead of Na+ also allows rapid growth; but in a mutant deficient in ornithine--oxo-acid aminotransferase, only pyrroline-carboxylate or proline can replace Na+. The amino acid pool of cells growing slowly in potassium aspartate contains proline at a low concentration which increases upon addition of proline (but not Na+) to the medium. Thus, Na+ addition does not increase the synthesis of proline, but proline or pyrroline-carboxylate acts similarly to Na+ either in preventing some inhibitory effect (by aspartate or the accumulating NH4+) or in overcoming some deficiency (e.g. in further proline metabolism.

Amino Acids↗
PubMed1978

Bronchial carcinoids and hormonal disorder.

The relationship between bronchial carcinoids and hormonal disorder is reviewed in the light of a study of 24 patients with carcinoid tumors of the bronchus. In this series, two patients presented with manifestations of the polyendocrine disorder. The common origin of carcinoid tumors and other APUD cells from neural crest ectoderm provides a common denominator in the association of carcinoid tumors of the bronchus and adenomas, or carcinoma of associated endocrine organs.

Adenoma↗
PubMed1977

The cellular structure of bronchial carcinoids.

A histological and electronmicroscopic study of bronchial carcinoids indicated that these tumours are argyrophilic in keeping with their occurrence in tissue of embryologically foregut origin. Normal bronchi contain cells that resemble, in their electronmicroscopic content, intestinal Kultschitzky-type cells. Characteristic of the carcinoid cell is the presence of intracellular neurosecretory granules seen on electronmicroscopy despite the apparent absence of argentaffin granules under light microscopy.

Bronchial Neoplasms↗
PubMed1977

Bronchial adenoma. A clinicopathologic study.

Among 28 patients with bronchial adenomas, 24 adenomas (86%) were of the carcinoid type. The 28 bronchial adenomas provided an incidence of 0.6% of all primary lung tumors seen in our institutions. There was a slightly greater preponderance of female patients and a greater incidence of the lision occurring in the right bronchopulmonary tree than the left. Symptoms of bronchial adenoma may exist for many years before the condition is diagnosed, and prolonged survival is recorded, even in the absence of surgical treatment. Although pneumonectomy was performed in several patients, lobectomy, bronchoplastic procedures, or sleeve resection of the affected area are generally recommended.

Adenoma↗
PubMed1976

Aspects of treatment. The anatomical basis for portal decompressive surgery.

Definitive surgical techniques used in the treatment of portal hypertension all aim to achieve portal venous decompression. The historic development of the various procedures currently employed provides a broad repertoire of surgical operations. Each of the procedures merits consideration and may be specifically indicated in a given situation. Description of the operative steps emphasizes the importance of the anatomical relationships of the various structures.

Blood Vessel Prosthesis↗