Gallium-67 scans in children with solid tumors.

Twenty pediatric patients with malignant disease were studied by whole body gallium scans. Seven had Hodgkin's disease, five had soft tissue sarcomas, three had neuroblastomas, two had Wilm's tumors, and one each had a hepatoblastoma, embryonal cell carcinoma, and sacrococcygeal teratoma. Of 50 sites studied, there was a true positive result in 17%, and in 58% there were false negative results. The method served best in patients with Hodgkin's disease, where the true positive rate was 64%. In no instance did the gallium scan affect the clinical management of a patient.


Idiopathic multicentric osteolysis.

A 59 year old while female with striking carpal and tarsal osteolysis is reported. The process primarily involves the carpals and tarsals but includes other sites. The pertinent literature is reviewed and a simplified classification of idiopathic multicentric osteolysis is presented. Idiopathic multicentric osteolysis may be sporadic but can demonstrate either dominant or recessive inheritance. There may or may not be associated nephropathy. The underlying mechanism appears similar in all variations of this condition. Gorham's disease, the Winchester syndrome, and other osteolytic conditions which may predominantly affect the tarsal and carpal bones most likely are totally different processes, unrelated to idiopathic multicentric osteolysis.


Myositis ossificans circumscripta: a benign lesion with a malignant differential diagnosis.

Localized areas of active myositis ossificans, occurring without a clear history of antecedent trauma, have been referred to as a "pseudo-malignant osseous tumor of soft tissue." This lesion may be mistaken both roentgenographically and pathologically for a malignancy. The roentgenographic signs which favor a diagnosis of non-neoplastic heterotopic bone formation include a lucent zone between the lesion and the adjacent bone, an intact underlying cortex, diaphyseal location, dense calcification in the periphery, and loss of volume on serial films.


Lesions resembling gout in patients with rheumatoid arthritis.

Although roentgenographic appearances are seldom important in establishing the diagnosis of rheumatoid arthritis or gout, atypical appearances of individual lesions may confuse the distinction between these two conditions. Sixteen patients with rheumatoid arthritis were selected to illustrate joint and soft tissue lesions which resemble gout. The lesions are divided into five broad categories on the basis of the appearance and sites of bone erosion as well as the nature of soft tissue changes. Symmetrical bilateral joint involvement was found to be especially helpful in distinguishing rheumatoid arthritis from gout.


Bronchopulmonary foregut malformations. A unifying etiological concept.

Two cases of congenital bronchopulmonary foregut malformation are reported and another 27 cases reviewed and the findings analyzed. The left lower lobe and the entire right lung are the most common locations of pulmonary involvement. The distal portion of the esophagus or cardioesophageal junction was the most common site of communication (83%). The majority of the patients (60%) presented in the first eight months of life, and the incidence in females was nearly twice that in males. Chronic cough, recurrent pneumonias and respiratory distress were the most common clinical findings, whereas two patients were totally asymptomatic. The esophagogram was the single most useful diagnostic procedure (82%). The microscopic structure of the congenital fistula resembled esophagus, bronchus or both. Surgical treatment was curative in most instances. Sime deaths occurred prior to corrective surgery, whereas the postoperative deaths in most instances were related to severe associated congenital anomalies. We believe a common embryologic pathogenesis leads to the formation of a variety of bronchopulmonary foregut malformations. These bronchopulmonary foregut malformations include intralobar and extralobar sequestrations, pulmonary sequestration with patent, or involuted--partial or complete--gastroesophageal communication, esophageal or gastric diverticula, and esophageal or bronchogenic duplication cysts.


Neuroepithelial (colloid) cysts. Pathogenesis and unusual features.

A brief history of the theories of pathogenesis of the origin of neuroepithelial cysts is presented. An origin more diffuse than the paraphysis seems most likely in our opinion, and we attempt to substantiate this theory with several of the cases from our series. One posterior third ventricular neuroepithelial cyst and one in the fourth ventricle are demonstrated roentgenographically. Also included in our series are a case showing suprasellar calcification on plain skull roentgenograms, not previously reported in neuroepithelial cysts, and a case with a cyst measuring 9 cm, the largest neuroepithelial cyst yet reported.


Optimal tomographic technique to demonstrate common bile duct stones. An in vitro study.

Six degree and 10 degree circular modes represent the optimal methods available for intravenous cholangiography with tomography within the technical limitations and constraints outlined in this study. The 10 degree mode is superior in the presence of superimposed gas. Ten degree linear tomography is an efficient method for determining the level of the common bile duct but is not the optimal method for obtaining image detail. Thin secretion unidirectional or pleuridirectional modes are occasionally helpful in delineating fine details. The zone of focus is very narrow, permitting very limited sampling within the usual zone of interest. These modes are inefficient in determining the level of the duct and produce less useful image detail than 10 degree circular tomography for ducts of normal, or slightly larger than normal diameters. They are seldom indicated as the primary modality in tomography of the common bile duct.


Successful intravenous cholecystocholangiography in the jaundiced patient using meglumine iodoxamate (Cholovue).

A clinical trial of meglumine iodoxamate (Cholovue) for intravenous cholangiocholecystography in 18 patients with elevated levels of serum bilirubin was performed. Ten to 30 cc of a 40% aqueous solution of the agent were given intravenously over a ten minute period and roentgenographic examinations conducted to document the agent's effectiveness, to determine optimal levels of dose, and to assess its safety. Common bile duct and gallbladder visualization was obtained in a surprisingly large number. The agent was effective with bilirubin levels up to 6.5 mg %. The optimal dose in patients with elevated bilirubin is probably in the range of 20 cc. Despite intensive monitoring, there were no important adverse clinical nor laboratory reactions observed. The new agent appears to offer a significant improvement over Cholografin, particularly with respect to patients with elevated bilirubin levels.


Griffiths' point: critical anastomosis at the splenic flexure. Significance in ischemia of the colon.

Griffiths' point is defined as the site of (a) communication of the ascending left colic artery with the marginal artery of Drummond, and (b) anastomotic bridging between the right and left terminal branches of the ascending left colic artery at the splenic flexure of the colon. It is upon this critical point at the splenic flexure that collateral circulation between the superior mesenteric artery and the marginal artery branch of the inferior mesenteric artery supplying the descending colon is dependent. Analysis of arteriographic studies shows that anastomosis at Griffiths' point is present in 48%, poor or tenuous in nine percent, and absent in 43%. This critical point is of significance in occlusive vascular impairment of the left colon, both in spontaneous instances and following surgical ligation of the inferior mesenteric artery, and in "nonocclusive" ischemic colitis. Its relationship to arteriosclerotic stenoses and low flow states is discussed. Individuals with absence of dependable anastomoses at Griffiths' point at the splenic flexure may be particularly vulnerable to low perfusion states and develop the syndrome of ischemic colitis. Complete arteriographic evaluation is necessary in ischemia of the colon. This includes particularly assessment of atherosclerotic changes at or near the ostia of the major visceral arteries and the vascular arrangement at Griffiths' point.


Angiography and ultrasonography. A comparative study of abdominal aortic aneurysms.

Ultrasound is presently the diagnostic procedure of choice in pulsatile abdominal masses. The ease and accuracy of this method have many advantages over aortography, and ultrasonography can accurately define the size of an abdominal aortic aneruysm. In addition, a normal aorta with an overlying mass, or a tortuous aorta which feels unusually prominent, can be detected, and aortography may not be necessary. Although ultrasound can detect involvement of iliac arteries, it does not allow assessment of the position of the aneurysm relative to the renal arteries, or detect involvement of other branch vessels of the aorta. Ultrasound is more accurate that clinical examination, plain roentgenography, aortography, or isotope aortography in the diagnosis of abdominal aortic aneurysms.


Combination of conservative surgery and irradiation for cancer of the breast.

In patients with relatively advanced local or axillary disease, or both, a simple mastectomy followed by irradiation gives the best local and regional control rates. From the existing data, one can state unreservedly that women with early breast cancer take no chance on their life by having a treatment method which preserves the breast. In conjunction with the wedge excision, even if the axilla is clinically negative, a dissection of the low and central axilla brings enough information to decide on elective chemotherapy.


Squamous cell carcinoma of the oral tongue and floor of mouth. Evaluation of interstitial radium therapy.

From January, 1965, to December, 1972, 46 patients with squamous cell carcinoma of the floor of the mouth and 102 patients with squamous cell carcinoma of the oral tongue were treated at M.D. Anderson Hospital and Tumor Institute by interstitial irradiation alone or in combination with external irradiation. Through the years the combination of radiation therapy modalities has been adjusted in an attempt to improve local control, keeping complications to a minimum. In this paper we analyze local control, causes of failure and complications as related to the primary size (T stage) and radiation therapy techniques employed.


Combined radiation therapy and 5-fluorouracil for advanced squamous cell carcinoma of the oral cavity and oropharynx: a randomized study.

In 1961, a randomized study was begun at the University of Wisconsin Medical Center in which the treatment of advanced squamous cell carcinoma of the head and neck with radiation therapy was compared with combined treatment with radiation therapy and 5-Fluorouracil. One hundred and thirty-six patients with primary lesions in the oral cavity, the base of the tongue, and the oropharynx were analyzed. Both local control and survival were better in the combined treatment group than in the group with radiation therapy alone. However, in only the oral cavity patient population was the difference statistically significant. Both acute and late complications were also increased in this group of patients who received combined treatment.


Carcinoma of the oropharynx. Results of megavoltage radiation therapy in 305 patients.

Three hundred and five patients with oropharyngeal carcinomas received linear accelerator radiation therapy at the Stanford University Medical Center between 1956 and 1973. All were staged by the TNM system, using the UICC Classification of 1962. Actuarial five year survival for patients with tonsil cancers ranged from 50% to 18% for those with T1 and T3 lesions, respectively. Disease-free survival was higher than actuarial survival for patients with T1 and T2 lesions, reflecting an alteration of the latter curves by deaths from intercurrent diseases and second primary malignancies. Actuarial survival for patients with base of the tongue carcinomas was approximately 35% for those with T1 and T2 primary lesions and 22% for patients with T3 carcinomas. Considering all oropharyngeal sites of involvement together, clinically involved cervical lymph nodes were controlled by radiation therapy alone in 60 of 91 patients with N1 nodal involvement (67%), in twelve of 25 with N2 neck disease (48%) and in 46% of those patients with N3 involvement (34 of 74). Eighty-nine percent of patients whose lymph nodes were not controlled by radiation therapy alone also had uncontrolled primary cancers. Over 90% of the patients whole cervical lymph nodes were initially uninvolved remained free of late nodal metastases if at least the regional (first echelon) lymph nodes were included in the primary treatment fields. The results of a randomized trial which compared surgery and radiation therapy alone and the two modalities in combination for the treatment of a limited number of patients with advanced cancers of the oropharynx, supraglottic larynx and hypopharynx suggest that surgery alone is not the treatment of choice.


Non-randomized comparison of preoperative irradiation and surgery versus irradiation alone in the management of carcinoma of the tonsil.

This is a non-randomized comparison of 98 patients with epidermoid carcinoma of the tonsil treated by preoperative irradiation and surgery and 97 patients receiving irradiation alone. Patients treated with preoperative irradiation received, in most instances, 3,000 rads tumor dose in three weeks through ipsilateral portals, followed within two to six weeks after completion of therapy by an en bloc tumor resection and radical neck dissection. The group treated with irradiation alone received tumor doses in the range of 5,500-6,500 rads in six weeks. No significant difference was noted in the survival yielded by either treatment modality. Both treatment modalities were equally effective in controlling the tumor in the metastatic ipsilateral lymph nodes. In selected cases, a combination of both modalitites may offer better results, but this remains to be proved.


Initial comparative response to peak pions and x-rays of normal skin and underlying tissue surrounding superficial metastatic nodules.

Given the limitations of available material and methods for measuring skin response, the relative biological effectivenss (RBE) for the development and healing of skin reaction to pions in this experiment is 1.43. This is based on data obtained from a patient with malignant melanoma, in whom multiple skin nodules and the surrounding normal skin were randomized into three dose levels for pions and x-rays. The RBE for skin reaction was obtained while the skin tumor nodules appeared to regress at least as rapidly with pion therapy as with x-rays. Without benefit of adequate observation of time required for nodule regrowth, any estimate of tumor RBE is speculative.


Initial evaluation of reduced fractionation in the irradiation of malignant epithelial tumors.

From July, 1971, through June, 1974, 170 patients underwent radiation therapy with reduced fractionation at the Milwaukee County General Hospital and the Wood Veterans Administration Hospital. One or two fractions per week were delivered for five to seven weeks to a total dose based on the tolerance of normal tissues predicted by the nominal standard dose (NSD) hypothesis of Ellis. Three groups of patients were selected from this heterogeneous population for detailed analysis--carcinomas of the skin, breast, and lung. The 72 patients evaluated provide useful data in regard to acute and subacute reactions. Short term assessment of local tumor control in relation to surrounding normal tissue response is similar to that with conventional fractionation for each of these malignant epithelial tumors.


Patterns of failure in intracranial astrocytomas after irradiation: analysis of dose and field factors.

The choice of tumor dose and treatment volume are the two most important radiation factors influencing survival in glioblastomas. Patients treated to their whole brain survive longer than those treated with limited fields. Glioblastomas treated with over 5,000 rads (1,300 rets) survive longer than those treated with smaller doses. Other factors affecting survival are: the pathological grade; age at diagnosis; and surgical treatment performed. Failure patterns in glioblastomas represent intrinsic qualities of the tumor, the host, and the treatment employed. They dictate the strategy to follow. Perhaps some of these are unaffected by irradiation. An increase in dose and the extension of fields in glioblastomas have produced a gain in both the quantity and the quality of survival. The whole brain is treated (5,000-6,000 rads) and the target volume is boosted to 7,000 to 8,000 rads. Grade II astrocytomas perhaps should be treated with whole brain irradiation (4,500 rads) and a boost to the target volume of an additional 1,000 rads.


Pharmaco-kinetics of current skeletal-seeking radiopharmaceuticals.

The blood clearance of all current bone-seeking radiopharmaceuticals is biexponential during the first four hours after injection. Exponent I represents bone uptake and its clearance half-time is less than 30 min. Exponent II represents mainly urinary excretion and its clearance half-time varies from 168 to 512 min. The blood background is highest with 99mTc-labeled polyphosphate (Tc-Poly) and lowest with sodium fluoride (F-18); 99mTc-labeled diphosphonate (Tc-Dip) and 99mTc-labeled pyrophosphate (Tc-Pyro) show intermediate blood levels. The slower blood clearance of 99mTc-phosphate complexes in comparison with F-18 is due primarily to their increased protein binding. Tc-Poly blood clearance, which is slower than that of Tc-Dip and Tc-Pyro, is due primarily to its increased red cell binding and the larger size of its molecule. Bone uptake and urinary excretion of all 99mTc-labeled phosphate complexes are approximately the same: in the range of six to ten per cent in the blood, 30-33% in the urine, and 55-58 percent in the bone and other tissues. F-18 concentration in the bone is almost 1.5 times that of the 99mTc-labeled phosphate complexes. The sensitivity and resolution of lesions are identical for all 99mTc-labeled phosphate complexes and are far better than those for F-18. No toxicity is noted with the amount of phosphate present in the marketed kits, and it appears reasonable to use the minimal amount so long as efficiency is not compromised.


Effect of therapeutic irradiation on the immune responses.

The immune responses of 60 patients undergoing therapeutic irradiation were evaluated according to four anatomical sites irradiated. In vitro lymphocyte transformation tests with PHA, Con-A, and PWM and quantitative assays of IgG, IgA, and IgM were performed on blood obtained from each patient before and during therapy, and two weeks, two months, and six months after therapy. At these same testing intervals, skin tests with PPD, mumps antigen, Candida antigen, and SD-SK were performed. During irradiation, the mean values of all lymphocyte transformation tests were depressed, varying from 48% to 64% of pretreatment baseline. This depression persisted until about two months after completion of treatment. By six months, response rose to pretreatment values. When response was evaluated according to sites irradiated with all mitogens, the pelvic and pelvic plus abdominal groups showed consistently greater depression than the chest or head and neck groups. Radiation effected no significant changes in the mean values of IgG, IgA or IgM. A decrease in skin sensitivity was noted during radiation; 73% of the subjects responded positively before therapy while only 53% had at least one positive test during therapy. By two months postirradiation, 73% of the group clinically free of disease had positive skin tests. A comparison of clinical condition with test results is significant when one considers the 17 patients who developed metastatic disease or died from disease. The depression for all three mitogens during radiation therapy was greater for this group. Of the 17, only four had IgG levels in the normal range, and consistently fewer positive skin tests were demonstrated.


The spectrum of osteoblastoma.

Benign osteoblastoma is a rare tumor, more frequent in males, usually occurring in patients under the age of 30 years, and is seen most frequently in the spine, femur, tibia, and mandible. Its varied roentgenographic appearance may suggest a large osteoid osteoma or an aneurysmal bone cyst, but about one-fourth of cases present a picture consistent with a malignant neoplasm. The roentgen changes in the spine are frequently subtle and require care for identification. Differentiation from osteogenic sarcoma is sometimes difficult even with histological material, because some low grade osteogenic sarcomas contain areas resembling osteoblastoma. Conservative surgery is the treatment of choice for osteoblastoma.


Non-rheumatic acute mitral insufficiency caused by ruptured chordae tendineae.

Five patients with proved mitral insufficiency caused by ruptured chordae tendineae were examined. Two patients came to autopsy without cardiac cateterization. Three patients, who had cardiac cateterization and surgical replacement of their mitral valves, improved dramatically. Two additional patients have been clinically diagnosed and have had corroborative cardiac catheterization and are being observed in anticipation of possible future valve replacement. Similar findings in these seven patients include adult onset of a characteristic systolic heart murmur which mimics aortic valvular stenosis, acute pulmonary edema associated with massive mitral insufficiency in the face of a normal sized or only minimally enlarged left atrium, and variable size of the left ventricle. In none of the patients were there historical or physical findings of trauma or rheumatic or bacterial endocarditis. A wide spectrum of clinical courses may be explained by the variable number of ruptured chordae tendineae at the time of clinical presentation. Although the incidence and etiology are uncertain, we believe this entity is not uncommon. Myxomatous degeneration of the connective tissue of the heart was present, but the cause remains unknown.


Hemochromatosis: a disease often silent but not invisible.

Hemochromatosis is a disorder characterized by the association of portal cirrhosis with deposition of excess amounts of iron in the parenchymal cells of many organs. Arthralgia and arthritis occur in about 50% of patients. The role of the radiologist is often significant in the recognition of this condition because hemochromatosis may be unsuspected clinically since the hepatic cirrhosis is frequently inactive at the time the arthritis develops. The possibility of hemochromatosis should be considered when the characteristic involvement of the metacarpophalangeal, radiocarpal, and proximal interphalangeal joints of the hand and wrist is present. In addition, articular and fibrocartilage calcification is often noted, particularly in the knee, triangular cartilage of the wrist, hip, elbow, symphysis pubis, and shoulder. Although localized chondrocalcinosis may be seen in association with many disorders, as well as in asymptomatic elderly persons, generalized chondrocalcinosis is a significant finding and is commonly associated with hemochromatosis. Recognition of the typical distribution of the arthropathy plus its characteristic roentgenographic features should aid in the identification of patients with the disorder who do not demonstrate the typical clinical features of hemochromatosis.


Biliary ascariasis in children.

The ascaris is a common human parasite and has a world wide distribution. In areas where it is endemic, biliary complications are common. In our locality it occurs mainly in children, presenting with upper abdominal colicky pain usually without jaundice. We have analyzed the positive roentgenological findings of 67 cases which presented in one year. The findings on cholangiography are diagnostic. The worm is seen as a linear translucent filling defect in a dilated common bile duct. Usually it is only faintly outlined by thin tram lines and occasionally there may not be excretion of the contrast material. The attention of radiologists is brought to this condition and the appearances of ascariasis infestation of the intestines are also noted.


Roentgenology-pathology correlative study of neovascularity.

In an attempt to evaluate the histologic picture of what is shown on angiograms as neovascularity, several benign and malignant tumors were examined. New vessels (neovascularity) are large capillaries or sinusoids, and neither contain smooth muscle in their walls. The walls may contain some fibrous connective tissue. Puddling, laking, and staining represent the collection of contrast medium in small capillaries or sinusoids. Some tumors, such as hemangioma of the liver, cystadenoma of the pancreas, and angiomyolipoma of the kidney contained abnormal vascularity, but this was not composed of vessels which had arisen or developed anew, as there was smooth muscle in their walls, and this indicates that those vessels had been there from birth. In xanthogranulomatous pyelonephritis and chronic renal disease, the appearance of increased vascularity is the result of rearrangement of the normal vascular structures.


Intestinal malrotation in adults. Roentgenographic assessment with emphasis on isolated complete and partial nonrotations.

Intestinal malrotation may occur as an isolated deformity. It may involve either the proximal (duodenojejunal) or the distal (cecocolic) intestinal segment. A survey of 28 consecutive cases of rotational abnormalities in the adult population demonstrates a diversity of roentgenographic presentations. Twelve cases exhibited the classical form of nonrotation of the entire midgut. The rest showed isolated forms of complete and partial rotations as well as a variety of intermediary forms previously not reported in the literature. Familiarization with this concept avoids confusing interpretations and errors in the roentgenographic diagnosis.


Efficacy of pneumogynecography in the diagnosis of Meyer-Rokitansky-Küster-Hauser syndrome.

Twelve patients with Meyer-Rokitansky-Küster-Hauser syndrome were examined by means of pneumogynecography. The results obtained disclose the great diagnostic value of the method in this disorder.


Retrocecal appendicitis presenting with air in the subhepatic space.

Two cases of perforated retrocecal appendicitis presenting with the roentgen finding of an air containing subhepatic abscess are discussed. Although it is an unusual cause for air in the right subhepatic space, retrocecal appendicitis should be considered in the radiologist's differential diagnosis.


Complications of percutaneous transaxillary catheterization for arteriography and selective chemotherapy.

This report enumerates and analyzes the complications of percutaneous transaxillary catheterization encountered in 200 consecutive patients undergoing diagnostic arteriography, and 20 consecutive patients who had catheter placement for selective chemotherapy. Diagnostic arteriography led to minor complications in eleven percent and major complications in two percent. Risk correlated with the type of procedure, number of catheter exchanges and particularly, the presence of arteriographic risk factors, such as hypertension, bleeding tendencies, and advanced atherosclerosis. Therapeutic catheter placements had a 15 percent incidence of minor and a 20 percent incidence of major complications. Here, also, complications were more likely in the presence of the arteriographic risk factors. Suggested means for decreasing the hazards of the transaxillary catheterization include: exclusion of high risk patients, use of a proper puncture site, careful catheter manipulation, the fewest possible catheter exchanges, correct manual hemostatis following catheter withdrawal, and close observation of the patient after the procedure. Early surgical intervention is indicated in the presence of a progressively developing neural defect.


Arteriography of retroperitoneal lymphoma.

Arteriography was performed in 16 patients with various types of lymphoma involving the retroperitoneal space. The location and extent of the mass could be predicted in 15 cases, based upon displacement of major arteris or kidneys. Most of the studies demonstrated some degree of fine reticular neovascularity and staining within the mass; none showed extreme hypervascularity, coarse or ragged vessels, or pooling of contrast medium during the capillary phase. The differential diagnosis of lesions with this appearance includes metastases, sarcomas, neural tumors, and inflammatory masses. Arteriography may possibly prove to be of value in staging certain patients with lymphoma, although definitive assessment of its role must await further prospective studies.


Computerized reconstructive tomography applied to breast pathology.

Breast tumors can be clearly defined from the surrounding breast parenchyma by the use of computerized reconstructive tomography. Certain types of fibrocystic mastitis also can be distinguished from tumors, but other types of fibrous mastitis and probably fibroadenomas may not be distinguishable from tumors unless contrast material is used.


Analysis of cecal vasculature in the search for vascular malformations.

Four patients with gastrointestinal bleeding due to vascular malformations of the cecum are described with emphasis placed on the clinical, angiographic and pathologic features. Barium enema examinations were negative in all four cases and in three of four early venous filling identified the cecal vascular malformation. Postoperative angiographic studies of the cecal specimens using electron emission radiography were helpful in identifying these small lesions. The pathologic features and possible pathogenesis of this disorder are reviewed. Angiographic and microscopic studies in a control group of 60 post mortem and surgically extirpated cecums defined the normal circulation of the antimesenteric border. In this group, no vascular malformations were present.


Pulmonary metastases from intracerebral meningioma. Diagnosis by percutaneous needle aspiration biopsy.

A case of metastatic meningioma to the lung is reported and the recent literature reviewed. This case was diagnosed solely by cytologic examination of fine needle aspiration biopsy. Pulmonary metastases are relatively rare and the diagnosis by this method has not previously been reported.


Hazards of the intensive care unit.

Complications arise in the introduction, maintenance, and use of devices for life support and monitoring in an intensive care unit. Since recognition of such complications is frequently difficult in this clinical setting, the radiologist is often in a position to be the first to detect complications associated with the use of endotracheal and tracheostomy tubes, Swan-Ganz catheters, subclavian catheters, central venous pressure catheters, and intra-aortic balloons.


A device to measure roentgenographic structures.

A simple device and a nomogram are presented to permit rapid, accurate measurement of structures shown on roentgenograms. The arrangement is designed specifically for measurement of coronary vessels, but it can be adapted to other structures.


Villous adenomas of the colorectum.

During a ten-year period 258 patients with villous adenomas were seen at the Massachusetts General Hospital: seventy-four of these patients (29%) had invasive cancer that developed in adenomas. The operative mortality ascribed to removal of benign adenomas was zero, but for cancer arising in villous adenomas it was 3 per cent. Therapy often is difficult because of the size and location of the tumors. Methods of removal have been considered in detail.


[Schnyder's corneal dystrophy and hyperlipidemia (author's transl].

Five out of ten members of a kinship were found to be affected by Schnyder's corneal dystrophy. Hyperlipoproteinemia was present in five out of eight cases examined (3 times type II, twice type IV). In one case with corneal dystrophy lipid levels were in the normal range, in another case, a child, hyperlipidemia was present without corneal abnormalities. The interrelationship of Schnyder's corneal dystrophy and disorders of lipoprotein metabolism is discussed. It is concluded that patients with Schnyder's corneal dystrophy and their relatives should be screened for hyperlipidemia; prophylactic treatment should be instituted when cases with hypercholesterinemia are found.


[Ultrastructure of macular corneal dystrophy (Groenouw II): investigations of paracentral deep corneal layers (author's transl)].

Electron microscopic studies proved, that in cases of macular corneal dystrophy (Groenouw II) abnormal deposits of acid mucopolysaccharide are demonstrable in the different layers of the cornea in a polymorphic form. Because of the investigations now performed it can be established, that the opacities of the paracentral, deep corneal layers result from both dispersed vesicular and plaque-like deposits of storage material in the border area of the stroma and Descemet's membrane.


Halothane action on lymphocytes does not involve cyclic AMP.

Both theophylline and halothane inhibited transformation of human lymphocytes by phytohemagglutinin (PHA). Theophylline did not augment the inhibitory action of halothane and depressed PHA transformation of halothane-treated cells to the same extent as that of air-treated cells. Halothane- and air-treated lymphocytes, prior to PHA addition, had the same content of cyclic AMP. The addition of PHA to these cultures raised cyclic-AMP concentrations to the same extent in halothane- and air-treated lymphocytes. Halothane action on PHA-stimulated lymphocytes appears not to involve changes in cyclic nucleotide metabolism.


Pharmacologic modification of induced asthma.

Oral adrenergic substances (e.g., ephedrine) and phosphodiesterase inhibitors (e.g., theophylline) can have a prophylactic effect on natural or experimentally induced asthma by maintaining high levels of cyclic AMP in the target organ cells. This controlled, double-blind study evaluates these drugs alone and in a standard dosage combination in blocking asthma induced by the inhalation of pollen allergens among highly selected patients. The results support the claim that oral adrenergic drugs and xanthines can be useful in the prophylaxis of asthma.


[Bacteriological characteristics of Streptococcus agalactiae. Incidence and conditions of appearance of the pigmentation. Sensitivity to antibiotics].

From a bacteriological study of 137 strains of streptococcus agalactiae, it seems that this species is perfectly defined by bacteriological tests, the most characteristic of which is hydrolysis with hippuric acid. The brown pigment of the strains, the conditions for demonstration of which are described and discussed here, may also be an important characteristic for it is rare in streptococci. The pigment was extracted, its nature and role are discussed. The sensitivity to 12 antibiotics was studied; the beta-lactamines were the most commonly active.


[A practical method of numerical evaluation applicable to miniaturized technics of plaque assay].

When one wishes to titrate viruses by counting the number of infective foci on small surfaces of observation, one is rapidly limited by confluences which render counting impossible. Between the use of an all or nothing system which is not accurate and a total field of count, often impossible, there is an intermediate method already described and studied by Tippett, which is very little used in practice. We have performed the calculations again, drawn up reference values and given rules for choice of the field. Two examples show their practical use.


[The action of 2(alpha-hydroxybenzyl)-benzimidazole on 26 strains of bovine enteroviruses isolated in Algeria (author's transl)].

Bovine enteroviruses were first classified into two main groups on a serological basis. The ability to grow in the presence of 5 mug/ml of 2(alpha-hydroxybenzyl)-benzimidazole (HBB) has been reported to be characteristic of the strains belonging to group I. Twenty-six strains isolated in Algeria and previously serologically grouped were submitted to the action of GBB. The viruses of our group I (similar to La Placa's group I) exhibited the same propertie, whereas the strains of our group II were inhibited by GBB as are the strains belonging to La Placa's group II.


A lipid and lipoprotein profile of treated and untreated diabetics.

A group of 149 diabetics and 98 healthy subjects without evidence of diabetes or ischaemic heart disease were studied. Untreated diabetics under 40 years old and 40 years of age and over showed statistically raised fasting serum turbidity, triglycerides, and raised beta and pre-beta lipoprotein levels but not raised cholesterol levels over the age and sex matched normal subjects. Further, some 63% of all diabetics showed a distinct split pre-beta lipoprotein pattern as seen on polyacrylamide disc electrolphoresis as compared with 17% in the control group. Raised lecithin and phosphatidylethanolamine (PE) levels were found in male diabetics and raised PE levels in young diabetic women. In patients under treatment with insulin, chlorpropamide, or phenformin the diabetes was well controlled in most cases, but these patients did not have significantly lower lipid levels. Diabetics on a low carbohydrate diet showed improvement in triglycerides and pre-beta lipoprotein levels, but beta lipoproteins were not lowered. It is suggested that diabetics may benefit by the inclusion of clofibrate in the treatment.


Primary liver cancer associated with long-term oestrogen therapy.

A woman with primary liver cancer after nine years therapy with polyestradiol-phosphate is reported. The oestrogen was administered monthy by intramuscular injection for menopausal symptoms. This case suggests a possible association between long-term oestrogen therapy and the development of hepatic malignancy and also must direct attention to both hormone components in the evaluation of tumour development in users or oral contraceptives.


Bone and kidney lesions in experimental cadmium intoxication.

Young male rats were fed a diet containing cadmium (0, 10, 30, 100, and 300 ppm) so as to morphologically investigate the relationship between bone and kidney lesions caused by experimental cadmium intoxication. In the early stage of the experiment, before the occurrence of kidney lesions, ingeted cadmium caused osteoporotic changes in bone. In later stages, slight pathologic changes in the kdidney occurred in association with urinary excretion of cadmium. However, there was no evidence of osteomalacic change in bone during the 12-week experimental period. These findings suggest that cadmium may act primarily on bone, rather than secondarily through disturbances of the kidneys, which have some protective ability against cadmium intoxication in the early stage of ingestion of the metal.


Effect of aeration on the activity of gluconeogenetic enzymes in Saccharomyces cerevisiae growing under glucose limitation.

1. The effect of aeration on the key enzymes of gluconeogenesis was studied in baker's yeast (Saccharomyces cerevisiae) and in a nonrespiratory variant of S. cerevisiae grown under glucose limitation. 2. In baker's yeast phosphoenolpyruvate carboxykinase, hexosediphophatase and isocitrate lyase were completely repressed under anaerobic conditions. Their repression could be partially reversed by using intense aeration. 3. In the nonrespiratory variant these enzymes were absent independently of aeration. 4. Pyruvate carboxylase of baker's yeast showed maximal activity under anaerobic conditions. In the nonrespiratory variant pyruvate carboxylase had low activity under both anaerobic and aerobic conditions.


Localization of selenium in bacterial cells using TEM and energy dispersive X-Ray analysis.

Bacteria isolated from lake sediment samples reduced sodium selenite to elemental selenium. Finestructural observations were made on a number of different bacterial species cultured in the presence of sodium selenite. Examination of Escherichia coli and a Pseudomonas species revealed electron-dense deposits of irregular shape, composed of smaller units, within the cytoplasm but not on the cell wall and cell membrane. Cells of Aeromonas and Flavobacterium species exhibited conspicuous intranuclear fibrillary aggregates and different electron-dense inclusions. It appeared that the membrane structures were somewhat more easily stained in some bacterial cells after growth on agar plates containing sodium selenite. The deposits and fibrillary accumulations were interpreted to contain selenium on the basis of energy dispersive X-ray analysis. Control preparations and cells grown in the presence of sodium selenate were void of any fine-structural abnormalities. Alterations in fine structure are discussed in relation to the metabolism of selenium by bacterial cells and possible sites of inhibition.


Microfilament bundles in antheridial nuclei of Achlya ambisexualis E 87.

This is the first report of intranuclear microfilaments within gametangial nuclei of oömycetous fungi. Longitudinal sections of four to six microfilaments were frequently observed in meiotic antheridial nuclei of Achlya ambisexualis. Each microfilament measured approximately 7--10 nm in diameter. Spindle tubules (25 nm in diameter) were also observed within some of the nuclei possessing microfilaments.


The intramitochondrial location of cytochrome c peroxidase in wild-type and petite Saccharomyces cerevisiae.

Cytochemical and ultrastructural analysis of wild-type cells of Saccharomyces cerevisiae, grown aerobically in a glucose-limited chemostat, shows that cytochrome c peroxidase is localized between the membranes of the cristae, that is, in the intracristal space. This enzyme is thus positioned appropriately within the organelle to act as an alternate terminal oxidase for the respiratory chain. The proximity of the peroxidase to major sites of generation of its two substrates may account for the small leakage of hydrogen peroxide from yeast mitochondria, as compared with the larger outflow from mammalian mitochondria. In the cytoplasmic petite mutant, gross distortion of promitochondrial membrane arrangement is evident. Nevertheless, cytochrome c perioxidase activity is present in the same amounts as is found in wild-type cells, and is localized predominantly within annuli of membrane which constitute the promitochondria in these cells. No unequivocal evidence was obtained for the localization of catalase in microbodies or other organelles in either wild-type or petite cells.


Acid phosphatase localization in the fungus Whetzelinia sclerotiorum.

Acid phosphatase was localized by light and electron microscopy in chains of vacuoles in hyphal tip cells of Whetzelinia sclerotiorum. The enzyme was present in these vacuoles whether or not conditions favored extracellular acid phosphatase secretion. Apical vesicles, microbodies, Woronin bodies, and lipid bodies did not contain acid phosphatase. The implications regarding terminology of organelles in filamentous fungi are discussed with special reference to the fungal spherosome concept.


Effect of temperature on the viability of Bacillus stearothermophilus.

One of the obligate thermophilic bacteria, Bacillus stearothermophilus, was unable to grow at temperatures below 35 degrees C. About 80% of the population in the bacterial culture died at the temperatures, and the same extent of loss in either of the activities of oxygen consumption or synthesis of protein or nucleic acid of the organisms was observed. With the progress of death of the organisms, reduced nicotinamide-adenine dinucleotide came to be oxidized by the organisms, enzymes such as fructose-1,6-diphosphate aldolase, when the organisms were washed with phosphate buffer, were leaked out of the organisms, and an increasing amount of ribonucleoprotein was released into the culture medium. The change of the membrane state was then suggested to be one of the possible causes for the death of the organisms at the temperatures.


[Fructose 1,6-diphosphatase deficiency in 2 sisters].

The discovery of a fructose-1,6-diphosphatase deficiency in two sisters leads to the discussion of the various loading tests which are required for the diagnosis. The diagnosis may be discussed clinically with type I glycogenosis, and biologically with hereditary fructose intolerance. The specific characteristics of these disorders are analyzed as well as the problem of fructose induced hypoglucosemia. The failure of the treatment with folic acid in one of the cases leads to emphasize the suppression of prolonged fast in order to avoid acute accidents.


[Increment in height of the upper segment and bi-iliac diameter after menarche in young girls. Longitudinal study of 40 adolescents].

The growth in height, upper segment and biiliac diameter after the menarche has been studied in 40 girls followed longitudinally until the mean age of 18 years 3 months. The mean increase in height after the menarch was 7.3 +/- 2 cm., with significant individual variations. The upper segment was responsible for much of the total increase, which was greater with an early menarche. The percentage of the final height attained by the menarche was constant: 95.5 % +/- 1,2 %. After cessation in height growth, the biiliac diameter still increased for 75 % of the children. The median value for this increase after the menarche was 2 cm., with a significant scatter. The increase in these three parameters was in indirect correlation with the bone age: the less the bone age at the menarche, the greater the increase in height, upper segment and biiliac diameter.


Fine structure of the pancreatic islets in domestic fowl with special reference to the cell type and secretion.

The pancreatic islets of domestic fowl were investigated by electron microscope. The following results were obtained. 1. The A islet is composed of a great many A cells and a few D cells. It also contained only a few B cells which are situated mainly along capillaries. 2. On the contrary, the B islet is composed of a great many B cells and a few D cells. It also contained only a few A cells in its periphary. 3. Immature secretory granules within the Golgi complex are almost the same in size, shape and density among the three types of islet cells. Since there are quite distinct differences in these properties of mature secretory granules in the cytoplasm among the three types of islet cells, there may be a difference in the mode of maturation process among the three. 4. These granules are released from the three types of islet cells through a mechanism termed as emiocytosis.


An ultrastructural-cytochemical study on the proliferation of smooth endoplasmic reticulum induced by chlorobiphenyls (PCB) in the guinea pig liver cells.

The ultrastructural changes in the liver cells of guinea pigs induced by the oral administration of PCB were studied by electron microscopy; also electron-microscopic cytochemistry for glucose-6-phosphatase (G-6-Pase) activity was applied. Proliferation of smooth endoplasmic reticulum (sER) was the most prominent change observed in the liver cells, which remained as long as 90 days after the final administration. G-6-Pase activity was ultracytochemically demonstrated not only in the rough and smooth endoplasmic reticulum and the nuclear envelope in the liver cells of normal controls, but also in the proliferated sER in the liver cells of PCB-treated animals. The present investigation revealed that PCB stored in the animal body induced the proliferation of sER in the liver cells for a long time after the cessation of the treatment, and that sER in the liver cells, normally existing or proliferated, always showed positive activity of G-6-Pase.


Frequency of genes and heredity of AK types in the Polish population.

Types of the AK groups system were determined in a sample of the Polish population numbering 660 subjects. Two phenotypes were found: AK 1-1 with a frequency of 0-933, and AK 2-1 with a frequency of 0-067. Gene frequencies were AK1 = 0-967 and AK2 = 0-033. Distribution of phenotypes in 62 families with 195 children was consistent with the hypothesis according to which heredity of AK types depends on two codominant alleles.


Changes in the heart in chronic experimental alcoholism.

In studies on the effect of chronic experimental alcoholism on the heart, rats were given 15% (v/v) solution of ethyl alcohol ad libitum instead of water to drink for 8 months. Histologic examination revealed degenerative changes in the myocardial fibers, and histochemical examination diminished activity of oxidative enzymes.


Calcium pyrophosphate. Histological characterization of crystals in pseudogout.

Deposits taken from an acetabulum and the head of a femur and known to contain crystals of calcium pyrophosphate were examined by selected histological methods for calcium after the application of a variety of solvents. Treatment with 10% ferric chloride removed all calcium salts tested, except a birefringent crystalline component in the pyrophosphate deposits. This corresponds to the previous optical and morphological descriptions of calcium pyrophosphate as found in synovial fluids. Calcium pyrophosphate stains consistently only by the fluorescent morin method.


Neutrophilic leukocyte inclusions in colchicine intoxication.

Large, darkly staining, intracytoplasmic inclusions were observed in the neutrophils of a young woman after suicidal ingestion of colchicine. The polymorphonuclear neutrophils also contained intracytoplasmic and intranuclear vacuoles. Electron microscopy enabled further characterization of these morphologic changes that, although nonspecific, are consistent with certain known toxic effects of colchicine.


Late infantile neuronal storage disease with curvilinear bodies.

The brain and other organs of a case of late infantile neuronal storage disease were studied by light and electron microscopy. At the ultrastructural level, aggregates of typical curvilinear bodies were found in neurons and cells of every organ examined. Striking features not well documented in previously reported cases included numerous, large curvilinear bodies in proximal renal tubules and granulomas in the spleen. These findings are discussed in light of other reports of neuronal storage disease.


Ultrastructural alterations in livers with metastasis.

The electron microscopic examination of 13 biopsy specimens of livers that contained metastatic carcinoma revealed degenerative alterations of the mitochondria, cystic dilatation of the endoplasmic reticulum, increased amounts of osmiophilic material, some in various stages of autophagocytosis, and lipid vacuoles within the hepatocytes. In ten of 13 cases, the hepatocytes demonstrated mitochondrial paracrystalline inclusions. The observation of the latter structures in edematous hepatocytes containing phospholipid-rich osmiophilic deposits tends to confirm the experimental hypothesis that paracrystalline inclusions are caused by the precipitation of unmasked phospholipids. The spectrum of ultrastructural findings suggests hypoxia and impaired lipid metabolism of the hepatic tissue as a result of congestion and bile stasis caused by the tumor nodules.


[Periods of spontaneous discharges in paretic muscles. Low frequency rhythms of repetitive single, grouped and serial discharges (author's transl)].

Of 1800 patients examined electromyographically, 37 showed different forms of spontaneous low frequency periodical discharges in neuromuscular diseases. Besides the well-known high frequency bizarre discharges of 10-150 per sec in neuropathies and myopathies, low frequency periods of mostly polyphasic potentials are described as "low frequency bizarre discharge". Three types of these rhythms are distinguished: single, grouped, and serial discharges in various peripheral nerve and motor neuron and muscle diseases. The rate of the periods varied from 0.2 to 6 per sec, but was nearly constant in one and the same muscle. The discharge rate within the period may be higher, up to 150 per sec. The low frequency single discharges probably originate in the muscle fibers, the grouped and serial discharges possibly in the terminal branches of peripheral nerves. Rhythmical repetitive discharges may result from a reduction of stimulus threshold and accommodation  of muscle- and nerve fibers respectively. Grouped and serial discharges may also be provoked by nerve stimulation or voluntary innervation.


The incidence of spontaneous tumors of the central nervous system of Wistar rats.

The brains of 396 old albino rats of the breed Wistar-AF/Han-EMD were examined for spontaneous tumors of the CNS and the following tumors were diagnosed: 1 oligodendroglioma, 1 astrocytoma, 1 mixed glioma, 1 pleomorphic glioma, and 19 meningiomas. Thus the CNS tumor rate was 5.8%. In addition 6 micromeningiomas were found. Knowledge of the spontaneous tumor rate including the tumor incidence in the CNS of the animal strains used for these examinations is a necessary condition for the evaluation of the results of cancerogenicity tests. CNS tumors deserve particular attention because during recent years it was found that certain chemical compounds like for instance N-methyl-N-nitrosourea induce organ-specific tumors in the brain of rats. It is recommended, therefore, to always include the central nervous system in the autopsy and histologic examination of animals from cancerogenicity trials. For cerebral autopsy transversal sections through the different cerebral regions and histologic examination of transversal section surfaces of all tumors and suspected tumor areas are suggested.


[An electron microscopic and morphometric study of the gastric parietal cells of rats following administration of gastrin, histamine and cyclic 3',5'-adenosine monophosphate].

The ultrastructure of the gastric parietal cells was studied in rats affected by a genetic inductor of the hydrochloric acid secretion and its mediators in this process - histamine and cyclic 3', 5'-adenozinemonophosphate playing the role of the enzyme activators. All these stimulators caused similar changes in the cell structure. The square surface of the intracellular secretory tubules was shown to become 2,5 times larger, and that of the canaliculi - vesiculoid elements which seemed to be the cell membrane depot became 2,5 times less. It may be supposed that the gastric mucosa parietal cells are not the target-cells for pentagastrine (gastrine).


[The specificity of intracellular changes in chick embryo blastoderm during the latent period of embryogenesis].

Yolk inclusions, lipids and polysaccharides found in the chicken embryo blastoderm cells are utilized during the latent period of embryogenesis. The yolk outside the blastoderm is not utilized. A delay in the development of the embryo of first days of incubation is related to a switching over the metabolism from utilizaiton of intracellular nutrient material to assimilation of the extracellular yolk. In the course of morphogenetical movements of the embryo, in the process of gastrulation, took place an increased biosynthesis in the blastoderm cell membranes.


Adult (chronic) GM2 gangliosidosis. Atypical spinocerebellar degeneration in a Jewish sibship.

Two adult Ashkenazi Jewish siblings have had slowly progressive deterioration of gait and posture since early childhood, distal to proximal muscle atrophy, pes cavus, foot drop, spasticity, mild ataxia of limbs and trunk, dystonic features, and dysarthria. Vision and optic fundi are normal, verbal intelligence is stable, and no seizures have occurred. The sister of the patients died at 16 years of age with the same illness. Autopsy showed diffuse neuronal storage, predominating in subcortical areas, consisting of membranocytoplasmic bodies, zebra bodies, and complex lamellar structures. GM2 ganglioside was increased in her brain. Hexosaminidase A was decreased in serum and leukocytes of the living patients, and was in the range for carriers of Tay-Sachs disease in their parents. The disease found in this family represents a new, more indolent variant of GM2 gangliosidosis.


Degenerative alterations in the ventral cochlear nucleus of the guinea pig after impulse noise exposure. A preliminary light and electron microscopic study.

Guinea pigs were exposed to the noise of 40 shots of an alarm pistol held at a distance of about 60 cm. The ventral cochlear nuclei were studied in phase contrast and electron microscopy after both survival periods and longer periods of up to 55 days survival. Marked degeneration of primary cochlear nerve endings and of synapting secondary neurons of the posterior caudal part of the ventral cochlear nucleus (AVCN) and the octupus cell area (OCA) of the posterior ventral cochlear nucleus (PVCN) was found most distinctly after 5-55 days. As criteria of degeneration of the second neuron of the afferent auditory pathway we used: 1. The loss of the synapting nerve endings, mainly 'shrinking". 2. The formation of huge mitochondria in the second order neurons and their dendrites. 3. The phagocytosis by glial cells of nerve endings, of the second order neurons and of their dendrites. After 5 days survival time no distinct changes were found in the granular cell area of PVCN, where as all stages of degeneration could be found in OCA at this time. In the discussion of these findings it is concluded that additional studies of the morphology of the cochlear nuclei seem necessary, as these may lead to a better understanding of the pathology of hearing following heavy noise exposure.


Characterization of a virus associated with epidemic conjunctivitis in Thailand.

A strain of virus, named the A-E strain, was isolated from a patient suffering from acute haemorrhagic conjunctivitis during an epidemic of the disease in Bangkok in 1972. The virus had the characteristics of an enterovirus but was not neutralized by any known enterovirus antiserum. Cross neutralization tests indicated that the isolate was closely related to the J670-71 virus isolated in Japan. The virus produced conjunctivitis in rabbits and monkeys following conjunctival inoculation.


Reversible modification of pig heart mitochondrial malate dehydrogenase by pyridoxal 5'-phosphate.

1. Pig heart mitochondrial malate dehydrogenase incubated with pyridoxal 5'-phosphate at pH 8.0 and 25 degrees C gradually loses activity. Such inactivation can be largely reversed by dialysis or by addition of L-lysine or L-cysteine, and can be made permanent by NaBH4 reduction. 2. Modification of malate dehydrogenase with pyridoxal 5'-phosphate at 35 degrees C involves two phases, an initial inactivation which is reversible and a slower irreversible second stage. 3. The initial reaction between pyridoxal 5'-phosphate and malate dehydrogenase appears to involve reversible formation of a Schiff base with the epsilon-amino group of a lysine residue. 4. Inactivation of malate dehydrogenase by pyridoxal 5'-phosphate at 10 degrees C involves only the reversible reaction. 5. At 10 degrees C repeated cycles of treatment with pyridoxal 5'-phosphate and NaBH4 reduction lead to a stepwise decline in residual activity. 6. Apparent Km values for malate and NAD+ are unaltered in the partially inactivated enzyme. 7. NAD+ and NADH give only partial protection against pyridoxal 5'-phosphate inactivation. Substrates give no effect.


Ontogenetic study of a myelin-derived fraction with 2':3'-cyclic nucleotide 3'-phosphodydrolase activity higher than that of myelin.

A membrane fraction (SN 4), prepared from developing and mature rat forebrain by hypo-osmotic treatment of microsome (microsomal-fraction)-free myelin, appears to be closely related to the myelin-like fraction. Fraction SN 4 shows 2':3'-cyclic nucleotide 3'-phosphohydrolase activity higher than that of the parent myelin. Electrophoresis reveals a multitude of bands with the Wolfgram protein as the main component.


A product-inhibition study of bovine liver glutamate dehydrogenase.

1. Initial rates of oxidative deamination of L-glutamate with NAD+ as coenzyme, and of reductive aminiation of 2-oxoglutarate with NADH as coenzyme, catalysed by bovine liver glutamate dehydrogenase were measured in 0.111 M-sodium phosphate buffer, pH 7, at 25 degrees C, in the absence and presence of product inhibitors. All 12 possible combinations of variable substrate and product inhibitor were used. 2. Strict competition was observed between NAD+ and NADH, and between glutamate and 2-oxoglutarate. All other inhibition patterns were clearly non-competitive, except for inhibition by NH4+ with NAD+ as variable substrate. Here the extrapolation did not permit a clear distinction between competitive and non-competitive inhibition. 3. Mutually non-competitive behaviour between glutamate and NH4+ indicates that these substrates can be bound at the active site simultaneously. 4. Primary Lineweaver-Burk plots and derived secondary plots of slopes and intercepts against inhibitor concentration were linear, with one exception: with 2-oxoglutarate as variable substrate, the replot of primary intercepts against inhibitory NAD+ concentration was curved. 5. Separate Ki values were evaluated for the effect of each product inhibitor on the individual terms in the reciprocal initial-rate equations. With this information it is possible to calculate rates for any combination of substrate concentrations within the experimental range with any concentration of a single product inhibitor. 6. The inhibition patterns are consistent with neither a simple compulsory-order mechanism nor a rapid-equilibrium random-order mechanism without modification. They can, however, be reconciled with either type of mechanism by postulating appropirate abortive complexes. Of the two compulsory sequences that have been proposed, one, that in which the order of binding is NADH, NH4+, 2-oxoglutarate, requires an implausible pattern of abortive complex-formation to account for the results. 7. On the basis of a rapid-equilibrium random-order mechanism, dissociation constants can be calculated from the Ki values. Where these can be compared with independent estimates from the kinetics of the uninhibited reaction or from direct measurements of substrate binding, the agreement is reasonable good. On balance, therefore, the results provide further support for the rapid-equilibrium random-order mechanism under these conditions.


Dogfish M4 lactate dehydrogenase: reversible inactivation by pyridoxal 5'-phosphate and complete protection in complexes that mimic the active ternary complex.

Dogfish M4 lactate dehydrogenase, like the corresponding pig enzyme, is inactivated by pyridoxal 5'-phosphate through modification of a single essential lysine residue. The activity is completely protected in the complexes E-NAD+-oxalate, E-NADH-oxamate and E-(NAD+-pyruvate adduct), but only partially protected in E-NAD+, E-NADH, E-NAD+-oxamate and E-NADH-oxalate.


Evidence that phosphatidylcholine and phosphatidylethanolamine are synthesized by a single enzyme present in the endoplasmic reticulum of castor-bean endosperm.

Increasing concentrations of CDP-choline progressively inhibit the measured incorporation of CDP-[2-14C]ethanolamine into phosphatidylethanolamine catalysed by the ethanolaminephosphotransferase present in endoplasmic-reticulum membranes isolated from castor-bean endosperm cells. This inhibition parallels that observed during CDP-[Me-14C]choline incorporation and suggests that a single enzyme utilizes both these substrates.


Evidence of isosteric and allosteric nucleotide inhibition of citrate synthease from multiple-inhibition studies.

Citrate synthases from diverse organisms are inhibited by ATP and NADH. Evidence is presented, from multiple-inhibition studies on various citrate synthases, that ATP acts in all cases as an isosteric inhibitor at the acetyl-CoA site. On the other hand, NADH also acts isosterically with eukaryotic and Gram-positive bacterial citrate synthases, but behaves as an allosteric inhibitor specifically in the case of the Gram-negative bacterial enzyme. After desensitization to this allosteric inhibition, only the isosteric nucleotide inhibition, as found in other citrate syntheases, is observed.


Further evidence for the concept of bovine plasma arylesterase as a lipoprotein.

Purified preparations of bovine plasma arylesterase were obtained by isoelectric focusing of enzyme prepared by (NH4)2SO4 fractionation of plasma and chromatography on DEAE-cellulose and Sephadex G-200. Although the high-density-lipoprotein fraction (HDL2) of serum provides an alternative source of enzyme, the enzymic activity of preparations made from it is much less stable. The purified arylesterase preparation has a molecular weight of 440000 and a partial specific volume of 0.91 ml/g, properties indistinguishable from those of the less highly purified enzyme. Extraction with acetone and ether removes neutral lipids from the enzyme, but the resulting lipid-depleted preparation retains most of the phospholipid present initially. A partial specific volume of 0.81 ml/g and a minimum molecular weight of approx. 100000 were determined for the lipid-depleted preparations of arylesterase. The present results support the concept of bovine plasma arylesterase as a lipoprotein in its own right, rather than as an enzymic polypeptide that is loosely associated with the HDL2 fraction of serum.


Evaluation of equilibrium constants for the interaction of lactate dehydrogenase isoenzymes with reduced nicotinamide-adenine dinucleotide by affinity chromatography.

Rabbit muscle lactate dehydrogenase was subjected to frontal affinity chromatography on Sepharose-oxamate in the presence of various concentrations of NADH and sodium phosphate buffer (0.05 M, pH 6.8) containing 0.5 M-NaCl.  Quantitative interpretation of the results yields an intrinsic association constant of 9.0 x 10 (4)M-1 for the interaction of enzyme with NADH at 5 degrees C, a value that is confirmed by equilibrium-binding measurements.  In a second series of experiments, zonal affinity chromatography of a mouse tissue extract under the same conditions was used to evaluate assoication constants of the order 2 x 10(5)M-1, 3 x 10(5)M-1, 4 x 10(5)M-1, 7 x 10(5)M-1 and 2 x 10(6)M-1 for the interaction of NADH with the M4, M3H, M2H2, MH3 and H4 isoenzymes respectively of lactate dehydrogenase.


Purification and properties of a specific collagenase from rabbit synovial fibroblasts.

1. A specific collagenase from the culture medium of rabbit synovial fibroblasts was purified by gel filtration and ion-exchange chromatography. 2. The enzyme was homogenous on polyacrylamide-gel electrophoresis and showed only traces of contaminants when tested in gels with a non-specific antiserum. 3. The rabbit fibroblast collagenase could hydrolyse collagen both in solution and in fibrillar form. Viscometry showed that at 35 degrees C the purified enzyme could hydrolyse greater than 50 nmol of collagen/min per mg of enzyme. 4. The purified collagenase cleaved collagen in solution at either 24 degrees or 35 degrees C into the characteristic 1/4 and 3/4-length fragments. However, as compared with the impure enzyme, the purified enzyme at 35 degrees C had a much decreased capacity to further degrade the initial specific cleavage products. 5. The specific rabbit collagenase had a mol. wt. of approx. 32000 as estimated by sodium dodecyl sulphate-polyacrylamide-gel electrophoresis, and 35000 by gel filtration.


Immunochemical studies with a specific antiserum to rabbit fibroblast collagenase.

1. Antisera were raised against the collagenase from rabbit synovial fibroblasts and characterized by immunoprecipitation and immunoinhibition reactions. 2. Immunoglobulins from the antisera were potent inhibitors of the action of rabbit collagenase on both reconstituted collagen fibrils and collagen in solution. 3. The antibody-binding fragment, Fab', produced by digesting the IgG (immunoglobulin G) with pepsin, inhibited collagenase activity just as well as whole IgG. 4. A specific antiserum to the rabbit collagenase was raised by a multi-step procedure. An initial antiserum was made by injecting partially purified collagenase as a complex with sheep alpha2-macroglobulin into a sheep. The non-specific antiserum so obtained was used to produce precipitin lines with the purified enzyme, and these lines were used as antigen for the production of the specific antiserum. 5. An IgG preparation from the specific antiserum was a specific and potent inhibitor of the rabbit synovial fibroblast collagenase. Neutral metallo-proteinase activity secreted by the rabbit fibroblasts was not inhibited by the antibody to the rabbit collagenase. 6. Criteria for determination of the specificity of antisera are discussed.


Synthesis of tritium-labelled isopenicillin N, penicillin N and 6-aminopenicillanic acid.

1. Phenoxymethylpenicillin sulphoxide 4-methoxybenzyl ester was labelled with 3H in its 2-beta-methyl group. Its specific radioactivity was 362 mCi/mmol. 2. Removal of the side chain of this compound yielded the corresponding ester of 6-aminopenicillanic acid sulphoxide and coupling of the latter with the appropriate protected alpha-aminoadipic acid gave 4-methoxybenzyloxycarbonylisopenicillin N sulphoxide di-4-methoxybenzyl ester or the corresponding derivative of penicillin N. 3. Removal of the protective groups by hydrogenolysis and reduction of the sulphoxide group yielded 3H-labelled isopenicillin N or penicillin N. 4. 3H-labelled phenoxymethylpenicillin sulphoxide was obtained by hydrogenolysis from its 4-methoxybenzyl ester. Reduction of its sulphoxide group and subsequent removal of the side chain gave 3H-labelled 6-aminopenicillanic acid.


Behaviour of tritium-labelled isopenicillin N and 6-aminopenicillanic acid as potential penicillin precursors in an extract of Penicillum chrysogenum.

1. 3H was incorporated into solvent-soluble penicillin from isopenicillin N and 6-aminopenicillanic acid 3H-labelled in the 2beta-methyl group when the labelled compounds were incubated with a crude extract of Penicillum chrysogenum. 2. With a soluble protein fraction of the extract incorporation from isopenicillin N occurred on addition of phenyl-acetyl-CoA. 3. Labelled benzylpenicillin was isolated after incubation of the crude extract with phenylacetyl-CoA and isopenicillin and the addition of unlabelled benzylpenicillin as a carrier. 4. No incorporation of 3H into solvent-soluble penicillin was detected on incubation of these extracts with penicillin N.


The binding of nicotinamide-adenine dimucleotide to glyceraldehyde 3-phosphate dehydrogenase from Bacillus stearothermophilus.

The binding of NAD+ to glyceraldehyde 3-phosphate dehydrogenase (EC 1.2.1.12) from Bacillus stearothermophilus has been studied by measurement of protein fluorescence quenching. Slight negative co-operativity was observed in the binding of the third and fourth coenzyme molecules to the tetrameric enzyme. The first two coenzyme molecules were tightly bound. In this respect the enzyme resembles that from sturgeon muscle rather than that from yeast.


Isolation of membrane-bound renal kallikrein and kininase.

Fractions highly enriched in plasma membrane, endoplasmic reticulum or brush border were prepared from homogenized rat kidney cortex. Kallikrein was concentrated in the plasma-membrane fraction, but not in the brush border of the proximal tubules. Kininase II or angiotensin I-converting enzyme was localized in the brush-border membrane. It is suggested that kallikrein in the urine may originate from the plasma membrane of the distal tubules and the conversion of angiotensin I and the inactivation of bradykinin may occur on the lumen membrane of the proximal tubular cells.


Crystal shedding and acute pseudogout. An hypothesis based on a therapeutic failure.

Four patients with chondrocalcinosis of the knees volunteered for joint lavage. Preliminary experiments indicated that disodium EDTA and magnesium ions were potent solubilizers of CPPD crystals. The procedure was a therapeutic failure in that insignificant amounts of CPPD were removed and all 4 subjects developed postlavage attacks of pseudogout. It is hypothesized that the acute attack of pseudogout is a result of crystal shedding and may be triggered by any factor that enhances CPPD solubility.


Studies on FeSV induced sarcomata in sheep with particular reference to the regional lymphatic system.

Inocula of cultured sheep cells that had been transformed with FeSV were injected into the legs of sheep so that the changes in the cellular and humoral composition of the efferent lymph from the regional node could be studied throughout the immune responses. The times at which immunoblasts and specific antibodies appeared in the lymph were similar to those recorded during responses to conventional antigens. The antiboides were mainly 7S, G1 immunoglobulins directed against virion antigens on the membranes of the transformed cells.


Significance of arming, potentiating and blocking factors as correlates the tumour-host interaction in the hamster SV40 system.

The study of blocking factors requires in vitro assay of cell mediated immunity that parallels the in vivo response. By microcytotoxicity testing, progressor and immune peripheral blood lymphocytes caused significant target cell reduction. The cytotoxicity was specific as no cytotoxic effect was detected against unrelated normal as well as a malignant target cell lines. No anti-tumour effect was noted when progressor peripheral blood lymphocytes were evaluated in the Winn assay. In marked contrast, immune peripheral blood lymphocytes were capable of preventing tumour growth in the Winn assay. Furthermore, hamsters repeatedly immunized with irradiated SV40 tumour cells could resist a live cell challenge. Thus immune peripheral blood lymphocytes were chosen as the effector population to evaluate the abrogation ability of serum in the microcytotoxicity assay.


The lack of association of theta status and murine leukaemia virus content in the AKR.

Two AKR sublines appear atypical in possessing theta C3H. One of these two sublines - AKR/FuA - is notably resistant to lymphomata and is also characterized by reduced levels of the group specific murine leukaemia viral (MuLV) antigen. This suggested a possible association between theta status tumour susceptibility and viral content. Results here show no reduction in viral antigen titres in the other theta C3H tumour susceptible subline AKR/Cum, thus eliminating the possible association of theta status with the extent of MuLV replication.


Cytoplasmic receptor levels and glucocorticoid response in human lymphoblastoid cell lines.

The cytolethal response to treatment with prednisolone was investigated in vitro in eight human lymphoblastoid cell lines containing varying concentrations of specific cytoplasmic glucocorticoid receptors. A similar response was observed in seven of the lines irrespective of their concentration of cytoplasmic receptors and pharmacological doses of steroid, well above those required to saturate receptors in cell-free extracts, were required for a massive lethal response. One cell line derived from Burkitt's lymphoma was refractory to lethal effects even with pharmacological doses of steroid. A similar unresponsiveness to the cytolethal effect of prednisolone in vitro was observed in fresh lymphoblasts derived from patients with acute lymphoblastic leukaemia despite evidence of a satisfactory clinical response to therapy which included steroid. The resistance of human lymphoblastoid cells to treatment with glucocorticoids in vitro may result from a defect in activation subsequent to the binding of steroid to cytoplasmic receptors.


Plasma membrane associated enzymes of mammary tumours as the biochemical indicators of metastasizing capacity. Analyses of enriched plasma membrane preparations.

Plasma membranes from 6 spontaneously metastasizing and 4 non-metastasizing rat mammary carcinomata were isolated by discontinuous sucrose density gradient centrifugation of microsomal pellets. The starting microsomal fraction contained 40-50% plasma membranes as determined by the levels of 5'-nucleotidase activity, with a negligible amount of nuclear (1%), mitochondrial (5%) and lysomal (7%) contamination. Five distinct fractions (F1-F5) were banded at densities 1 X 09, 1 X 13, 1 X 15, 1 X 17 and 1 X 21 at 25 degrees C, in addition to a pellet (F6) obtained by centrifuging at 76,000 g for 17 h. The fractions F1 through F5, all contained various concentrations of membranous structures, while the pellet (F6) contained only amorphous materials as evidenced by electron microscopy. The F3 fraction at the gradient 1 X 15 had the highest specific as well as total activity of the plasma membrane marker enzyme, with aggregates of the least contaminated plasma membranes in vesicular forms. This fraction also had the lowest specific activity for glucose-6-phosphatase (smooth ER marker) and for beta-D-glucuronidase (lysomal marker), and therefore was considered to be the "cleanest" plasma membrane fraction. When the activity of 4 additional plasma membrane marker enzymes, i.e., alkaline phosphatase, phosphodiesterase I, nucleotide pyrophosphatase and alkaline ribonuclease was determined in the same F3 fraction, their levels were significantly lower in every metastasizing tumour than in the non-metastasizing ones, with the enzyme activity decreasing in direct proportion to the metastasizing capacity. On the other hand, the marker enzymes were high in all non-metastasizing tumours, with the activity seemingly increasing with the immunogenicity of tumour cells. There was no significant difference between the 2 groups of mammary tumours in the levels of sialic acid, hexosamine, phospholipid or cholesterol in the plasma membranes. Thus, the level of plasma membrane marker enzymes is considered an accurate indicator for metastasizing capacity in the rat mammary tumour system.


The succinic dehydrogenase and cytochrome c oxidase activities of guinea-pig skin after mild heat damage.

Succinic dehydrogenase and cytochrome c oxidase activities of guinea-pig ear skin were found to be less sensitive than oxygen uptake to mild heat damage. It therefore appears that the failure of oxygen uptake following thermal injury is not directly due to inactivation of the enzymes of the respiratory chain.


Lowering of innate resistance of the lungs to the growth of blood-borne cancer cells in states of topical and systemic stress.

The survival and clonogenic growth (measured in terms of colony forming efficiency (CFE) of intravenously injected (i.v.) Walker (W256) tumour cells in the lungs of rats was greatly enhanced by states of topical and systemic stress induced by the intraperitoneal (i.p.) injection of rats with a single dose of 10(-5)-10(-3) mmol g-1 body weight of adrenaline and other beta-adrenergic agonists, inflammatory agents (including local x-irradiation), convulsive seizures, "tumbling" or physical restraint. Lowering of innate resistance of the host to growth of seeded tumour cells induced by states of topical and systemic stress, and by the addition of an excess of lethally irradiated (LI) tumour cells to i.v. injected intact tumour cells, were all potentiated by treatment of rats with aminophylline, an inhibitor of cyclic AMP phosphodiesterase. Enhancement of tumour growth by systemic stress was inhibited by bilateral total or medullary adrenalectomy and is attributed to the release and actions of endogenous adreno-medullary hormones. Alpha-adrenergic and most non-adrenergic agents administered in maximum tolerated doses did not significantly affect host resistance to tumour growth in the lungs. These findings, correlated with measurements of cyclic AMP in the lungs of normal and stressed rats, suggest that changes in the resistance of the host to tumour growth involve changes in cyclic nucleotide metabolism in the target tissues (tumour bed); possible mechanisms of action of cyclic nucleotides in this respect are discussed.


Platelet dysfunction in vincristine treated patients.

Recent revival of interest in the use of vincristine (VCR) for the treatment of idiopathic thrombocytopenic purpura prompted us to evaluate the platelet function of our patients on VCR. Eighteen patients with acute lymphoblastic leukaemia (ALL) in remission, and nine children with solid tumours were studied on 80 occasions at different time intervals after their last VCR dose. A mildly elevated threshold for epinephrine-induced second phase aggregation and a delay in the onset of collagen-induced aggregation was found in patients with ALL not on VCR. Vincristine induced unobtainable second phase aggregation to epinephrine in 67%, 38%, 30% and to ADP in 53%, 13%, 33% of the patients 1 week, 2-3 weeks and 4 weeks respectively after administration. The thrombocytopathy was relative, not absolute, since collagen induced aggregation at all times. Platelet counts, uptake and release of serotonin, bleeding times, clot retractions and release of platelet factor 3 were normal. Platelet adhesion was abnormal in five of 12 patients tested. In vitro platelets are a hundred-fold less sensitive to VCR than in vivo. Cyclic adenosine monophosphate, cyclic guanosine monophosphate and dimethylsulfoxide do not protect platelets from VCR. The exact mechanism by which VCR abolishes second phase aggregation in patients is uncertain. Because of VCR's narrow therapeutic index between thrombocytopenia and thrombocythaemia, the use of VCR should be reserved for life-threatening haematologic disorders when treating non-malignant conditions.


Isolation of viral specific RNA from SV40 infected cells by viral DNA chemically linked to a cellulose matrix.

SV40 DNA fragments chemically attached to neutral cellulose powder with a water-soluble carbodiimide have been used to isolate late lytic viral specific RNA from virus infected cells. Exhaustive hybridization to SV40 DNA reveals that virtually all of the isolated RNA molecules contain SV40 specific sequences. Comparison with SV40 cRNA prepared with purified Escherichia coli RNA polymerase and a SV40 DNA I template suggests that the purity of the isolated SV40 specific RNA is very close to 100%. The background level for the nonspecific binding of RNA to a purified cellulose matrix is very low. Retention of nonspecific RNA by SV40 DNA-cellulose is only 1.5% of the viral specific RNA isolated under saturating conditions for the column. Sedimentation in neutral sucrose suggests that the major 16S viral specific RNA has been isolated largely intact.


Circular dichroism and ethidium bromide binding capacity of chromatin from cells temperature sensitive for the transformed phenotype.

Clone H6-15/163 is a clone of cells, originally derived from SV-40 transformed 3T3 cells, which express the transformed phenotype at low (32 degrees C) but not at high (39 degrees C) temperature. Chromatin was isolated from these cells grown at either temperature and studied by circular dichroism and for its ability to bind the intercalating dye, ethidium bromide. During the exponential phase of growth the chromatins of cells grown at either 32 or 39 degrees C are undistinguishable. Cessation of growth in confluent cultures results in marked changes in circular dichroism spectra and in ethidium bromide binding capacity of chromatin. The changes are much are much more pronounced at 39 degrees C (where the cells truly become quiescent) than at 32 degrees C (where cell proliferation continues although the number of cells per culture remains stationary). Temperature shifts and medium replacement also cause changes in chromatin structure, but the changes are again related to the extent of cell proliferation. It is concluded that the chromatin changes occurring in H6-15/163 cells and detectable by circular dichroism and ethidium bromide binding can be related to the proliferating activity of the cultured cells rather than to the expression of the transformed or untransformed phenotype.


A ribosome-independent, soluble stringent factor-like enzyme isolated from a Bacillus brevis.

A ribosome-independent synthesis of guanosine 5',3'-polyphosphates has been found in the soluble fraction of Bacillus brevis (ATCC 8185) extracts. The partially purified enzyme catalyzes the formation of both guanosine 5'-diphosphate 3'-diphosphate and guanosine 5'-triphosphate 3'-diphosphate, does not require 20% methanol to stimulate the rate of reaction, and is not stimulated by complexing with ribosomes of either Escherichia coli or B. brevis. The B. brevis enzyme system is not inhibited by RNase A or thiostrepton, and is only slightly inhibited by tetracycline. The pyrophosphoryl donor specificity of the B. brevis enzyme is similar to that of the E. coli ribosome-stringent factor system.


A comparison of ribosomal proteins from rabbit reticulocytes phosphorylated in situ and in vitro.

A comparison has been made between the ribosomal proteins phosphorylated in intact cells and proteins isolated from ribosomal subunits after modification in vitro by purified protein kinases and [gamma-32P]ATP. When intact reticulocytes were incubated for 2 h in a nutritional medium containing radioactive inorganic phosphate, one phosphorylated protein was identified as a 40S ribosomal component using two-dimensional polyacrylamide gel electrophoresis followed by electrophoresis in a third step containing sodium dodecyl sulfate. This protein, containing 99% of the total radioactivity associated with ribosomal proteins as observed by two-dimensional electrophoresis, is found in a nonphosphorylated form in addition to several phosphorylated states. These states differ by the number of phosphoryl group attached to the protein. The same 40S protein is modified in vitro by the three cAMP-regulated protein kinases from rabbit reticulocytes. Two additional proteins associated with the 40S subunit are phosphorylated in situ. These proteins migrate as a symmetrical doublet, and contain less than 1% of the radioactive phosphate in the 40S subunit. A number of phosphorylated proteins associated with 60S subunits are observed by disc gel electrophoresis after incubation of whole cells with labeled phosphate. These proteins do not migrate with previously identified ribosomal proteins and are not present in sufficient amounts to be identified as ribosomal structural proteins. Proteins in the large subunit are modified in vitro by cAMP-regulated protein kinases and ATP, and these modified proteins migrate with known ribosomal proteins. However, this phosphorylation has not been shown to occur in intact cells.


The oxidation of phenylhydrazine: superoxide and mechanism.

The oxidation of phenylhydrazine in buffered aqueous solutions is a complex process involving several intermediates. It can be initiated by metal cations, such as Cu2+; in which case EDTA acts as an inhibitor. It can also be intiated by oxyhemoglobin; in which case chelating agents do not interfere. Superoxide radical is both a product of this reaction and a chain propagator. The formation of O2- could be demonstrated in terms of a reduction of nitroblue tetrazolium, which was prevented by superoxide dismutase. The importance of O2- in carrying the reaction chains was shown by the inhibition of phenylhydrazine oxidation by superoxide dismutase. Hydrogen peroxide accumulated during the reaction and could be detected with catalase. The progress of this oxidation could be monitored in terms of oxygen consumption and by following increases in absorbance at 280 or 320 nm. The oxidation was markedly autocatalytic and superoxide dismutase had the effect of extending the lag period. The absorbance at 280 nm was due to  an intermediate which first accumulated and was then consumed. This intermediate appears to be benzendiazonium ion. The absorbance at 320 nm was due to a stable product, which was not identified. The time course of oxygen consumption paralleled the increase in absorbance at 320 nm and lagged behind the changes at 280 nm. Exogenous benzenediazonium ion accelerated the oxidation of phenylhydrazine and eliminated the lag phase. Benzenediazonium ion must therefore react with phenylhydrazine to produce a very reactive intermediate, possibly phenyldiazene. A mechanism was proposed which is consistent with the data. The intermediates and products of the oxidation of phenylhydrazine include superoxide radical, hydrogen peroxide, phenylhydrazyl radical, phenyldiazene, and benzenediazonium ion. This is a minimal list: others remain to be detected and identified. It appears likely that the diverse biological effects of phenylhydrazine are largely due to the reactivities of these intermediates and products.


Iodination of DNA. Studies of the reaction and iodination of papovavirus DNA.

Iodination of DNA by the reaction originally described by S. L. Commerford ((1971), Biochemistry 10, 1993) is extremely sensitive to the secondary structure of the DNA. Cytidines in denatured simian virus 40 (SV40) DNA react at a slightly slower rate than free cytidine monophosphate; hydrogen-bonded cytidines in SV40 form I DNA are iodinated considerably more slowly; elimination of the negative supercoils in form I DNA by conversion to form II or form III reduces reactivity even further. The residual reactivity of form II or form III duplex DNA is not due to preferential iodination of unpaired cytidines near phosphodiester bond breaks; rather iodination occurs throughout the molecule. Cytidine monophosphate has been used as a model for DNA, to enable spectral measurements of its reaction with iodine and T1C13. At temperatures above 42 degrees C and at pH 5.0, formation of 5-iodocytidine is limited by the rate of formation of an intermediate, probably 5-iodo-6-hydroxydihydrocytidine. At lower temperatures, the conversion of intermediate to product is rate limiting, but can be accelerated by lowering the pH. By appropriate adjustment of pH, or temperature, the formation of intermediate or its conversion to product can be accelerated. Iodination destabilizes the DNA duplex. Iodocytosines in SV40 DNA are preferentially removed by S1 nuclease. Heavily iodinated DNA does not reassociate normally, but DNA with only 5-10% of its cytosines iodinated appears to reassociate with normal kinetics, if duplex formation is measured by hydroxylapatite chromatography. Conditions are described to permit preparation of DNA, which reassociates normally, having a specific activity of 10(8) cpm/mug.


Prenyltransferase: the mechanism of the reaction.

The enzyme, prenyltransferase, which normally catalyzes the addition of an allylic pyrophosphate to isopentenyl pyrophosphate, has been found to catalyze the hydrolysis of its allylic substrate. The rate of this hydrolysis is markedly stimulated by inorganic pyrophosphate. Competition experiments with 2-fluoroisopentenyl pyrophosphate and inorganic pyrophosphate demonstrated that inorganic pyrophosphate stimulated hydrolysis by binding at the isopentenyl pyrophosphate site. Hydrolysis carried out in H218O or with (1S)-[1-3H]geranyl pyrophosphate show the C-O bond is broken and the C1 carbon of geranyl pyrophosphate is inverted in the process. These results are interpreted to favor a carbonium ion mechanism for the prenyltransferase reaction.


Subunit structure of human erythrocyte glycophorin A.

Glycophorin A is a sialoglycoprotein isolated from human erythrocyte membranes which seems to exist as stable dimeric complexes in the presence of sodium dodecyl sulfate. When analyzed by dodecyl sulfate acrylamide electrophoresis this molecule forms two PAS-stainable bands (PAS-U and PAS-2) which are reversibly interconvertible. This change in electrophoretic mobility is dependent on the concentration of dodecyl sulfate, the use of Trisbuffer systems, the protein concentration in the incubation mixture, and the duration and temperature of incubation before electrophoresis. Reducing agents do no influence the results. Chromatography of the sialoglycopeptides on Sepharose columns in dodecyl sulfate before and after heat treatment gave similar results. A small hydrophobic peptide (T-6) derived from glycophorin A was able to prevent reassociation of the monomeric subunits back to the higher molecular weight form. This peptide was able to bind to the subunit of glycophorin A, but not to the high molecular weight complex. These results are consistent with a model of glycophorin A composed of two subunits which can dissociate and reassociate in the presence of detergents. These subunits may interact via the hydrophobic portions of the polypeptide chains.


Studies on human serum high-density lipoproteins. Self-association of human serum apolipoprotein A-II in aqueous solutions.

Some of the solution properties of pure preparations of human serum high-density apolipoprotein A-II were studied by sedimentation equilibrium ultracentrifugation, conducted at different apoprotein concentrations and at several speeds. The concentration dependence of the apparent weight average molecular weight indicated that apolipoprotein A-II, when dissolved in 0.02 MEDTA (pH 8.6), undergoes self-association. Over a protein concentration range between 0.8 and 1.5 mg/ml, the self-association could best be described by a monomer-dimer-trimer step association, although indefinite self-association could not be ruled out. The equilibrium constants obtained were sufficient to describe the system over the concentration range investigated.


Phosphatidylglycerol biosynthesis in Bacillus licheniformis Resolution of membrane-bound enzymes by affinity chromatography on cytidinediphospho-sn-1,2-diacylglycerol Sepharose.

Cytidinediphospho-sn-1,2-diaclglycerol (CDP-diglyceride) has been covalently linked to Sephrose 4B via adipic acid dihydrazide spacer arm forming an effective affinity chromatography column.  This liponucleo-tide ligand and sn-glycero-3-phosphate are subtracts for the formation of 3-sn-phoshatidyl-1'-sn-glycero-3'-phosphate (PGP) catalyzed in both eukaryotic and prokaryotic organisms by sn-glycero-3-phosphate:  CMP phosphatidlytranferase (PGP synthetase).  Using this CDP-diglyceride Sephrose affinity column we were able to resolve the membrane associated 3-sn-phosphatidyl'1-sn-glycerol (PG) synthesizing system present in Bacillus licheniformis into two activities.  A PGP synthetase activity was adsorbed to the affinity column and was eluted using buffer containg CDP-diglyceride; a PGP phosphatease acactivity had no affinity for the column.  Both PGP synthase and PGP phosphatase of B.  licheniformis were associated with a membrane component of the cell as evidenced by sucrose gradient centrifugation, differential centrifugation, and solubilization by buffers containing detergent...


Multiple forms of oviduct progesterone receptors analyzed by ion exchange filtration and gel electrophoresis.

Resolution of the multiple forms of steroid receptors in small samples has been improved by two new techniques: preparative ion exchange filtration and electrophoresis in highly cross-linked polyacrylamide gels of varied concentration. These techniques were used in conjunction with protamine precipitation, gel filtration, and density gradient centrifugation to separate five forms of the progesterone receptor of chick oviduct cytosol. These complexes, numbered I to V in order of elution from agarose gel columns, have been characterized with respect to apparent molecular weight, shape, and relative net charge. Form I, which is eluted in the void volume after gel filtration of cytosol in hypotonic media, is heterodisperse with respect to sedimentation coefficient and electrophoretic mobility (Rf). Form I is converted to form III by KC1. Form II has the highest axial ratio and the highest Rf at pH 10.2. This 4.2S complex can be extracted from DEAE filters, but not from protamine-precipitated cytosol, by 0.3 to 0.5 M KC1. Form III is slightly smaller (3.9S) and less asymmetric than form II. It is relased from DEAE filters and protamine-precipitated cytosol by 0.15 M KC1 and displays increased Rf upon purification. Forms II and III correspond to the B and A components described by W. T. Schrader and B. W. O'Malley ((1972), J. Biol. Chem 247, 51). Form IV may result from the proteolytic cleavage of forms II and/or III. Form V is a globular polypeptide obtained in the presence of certain divalent cations. This complex has been named the "mero-receptor" since it is the smallest part or fragment of the receptor that contains the steroid-binding site.


Changes in poly(adenosine diphosphate-ribose) and poly(adenosine diphosphate-ribose) polymerase in synchronous HeLa cells.

An antibody has been prepared which is highly specific for poly(adenosine diphosphate-ribose). Neither poly(A), DNA, nor a variety of adenine-containing nucleosides or nucleotides were effective in competing with poly(ADP-ribose) for binding to the antibody. Of all compounds tested, only adenosine diphosphate-ribose competed for binding to the antibody. Unlabeled poly(adenosine diphosphate-ribose) was about 10 000 times more effective in competing with labeled polymer for antibody binding than was adenosine diphosphate-ribose. Using the antibody, the amount of poly(adenosine diphosphate-ribose) was found to increase from early S phase to a peak at mid S with a second, even larger increase seen at the S-G2 transition point in synchronously dividing HeLa cells. Pulse labeling of the polymer with [2-3H]adenosine was also maximal at the same time points. Changes in the levels of poly(adenosine diphosphate-ribose) polymerase activity measured in isolated nuclei coincided with the changes in amounts of polymer present in intact cells during progression from S phase into G2.