Quantitative determination of specific IgE antibodies to Echinococcus granulosus and IgE levels in sera from patients with hydatid disease.

High serum IgE levels were found in eighty-nine patients with hydatid disease. Specific IgE antibodies to E. granulosus hydatid fluid or to a pure E. granulosus antigen were isolated using immunoabsorbents and quantified by a radioimmunoassay. The procedure made it possible to quantify, for the first time, the concentration of IgE antibodies in units per millilitre. Significant levels of IgE antibodies were demonstrated in twenty-three out of thirty-nine patients, by the use of standardized hydatid fluid antigens. The amount of IgE antibodies to E. granulosus was not related to serological findings. However, a highly significant correlation was obtained between levels of total serum IgE and IgE antibodies. A pure antigenic fraction prepared from hydatid fluid and known to be specific for E. granulosus was shown to be the most potent antigen reactive with IgE antibodies. The relationship of IgE antibodies to the viability of the hydatid cyst and to the serum IgE level is discussed.


The allergens of Schistosoma mansoni. II. Further separation by sephadex G-200 and ion-exchange chromatography.

A total of thirty-five antigen fractions were prepared from adult Schistosoma mansoni by extraction into borate-buffered saline, precipitation at pH 4-6, gel-filtration on Sephadex G-100 and G-200, and ion-exchange chromatography on CM- and DEAE-cellulose. The allergic activity of these antigens was assayed by a modified Prausnitz-Küstner (P-K) type reaction in rats. The results showed that the allergen-reagin axis in rat schistosomiasis is a multicomponent system involving molecules of widely different chemical nature and molecular weight, rather than a simple, single antigen-antibody interaction. The significance of these findings to the use of purified antigens for the diagnosis of schistosomiasis in the field is discussed.


The immunological response of the rat to infection with taeniaeformis. IV. Immunoglobulins involved in passive transfer of resistance from mother to offspring.

Weanling rats born of mothers infected with Taenia taeniaeformis were found to be passively protected against homologous challenge. Cross-fostering of normal suckling rats onto immune mothers established that passive transfer occurred via the colostrum and milk. Immunoglobulin fractions containing gammaA from immune colostrum were fed to 12-14-day-old rats for 4 days via stomach tube. Significant passive protection against challenge with T. taeniaeformis was achieved with gammaA from one of three colostrum pools. The effect of colostral gammaA preparations on the infectivity of freshly hatched oncopheres of T. taeniaeformis was measured by the intra-intestinal inoculation of immunoglobulin solutions into isolated gut loops containing hatched eggs of the parasite. gammaA from one of three pools of immune colostrum caused a significant reduction in the number of parasites which reached the liver. This appears to be the first time that protective activity against a helminth infection has been achieved with gammaA. A fraction of immune colostrum containing both 7Sgamma1 and 7Sgamma2 immunoglobulins was found to confer passive protection when inoculated parenterally. In view of the prolonged period of absorption (ca 18 days) of 7S immunoglobulins from the gut by the suckling rat, it seems likely that these antibodies are primarily responsible for the natural passive transfer of protection from mother to young.


Use of the local anesthetic lidocaine for cell harvesting and subcultivation.

Cell suspensions from monolayer cultures of 3T3, SV-3T3, BHK, BS-C-1, or macrophages, were prepared by brief exposure of the cultures to the amide anesthetic lidocaine. Cells were subcultivated six times without marked impairment of plating efficiency. The method should be applicable to physiological, biochemical, or immunological studies in which exposure of cells to proteolytic enzymes is to be avoided.


Establishment of two cell lines from embryonic tissue of the tobacco hornworm, Manduca sexta (L).

Two cell lines were derived from primary cultures of embryonic tissue of the tobacco hornworm, Manduca sexta (L.). The cell lines were maintained on hemolymph-free synthetic insect medium. Cytogenetic and immunoligical identification of the lines were carried out. Techniques for obtaining the line and medium, subculturieng and freezing procedures for long-term storage, and the morphological and growth characteristics are described.


The immunological response of the rat to infection with Taenia taeniaeformis. V. Sequence of appearance of protective immunoglobulins and the mechanism of action of 7Sgamma2a antibodies.

Passive transfer of immunity to Taenia taeniaeformis was achieved with serum taken 14, 21, 49 and 63 days after infection. The protective capacity of serum collected at 14 and 21 days resided in the 7Sgamma2 immunoglobulins and appeared to be partics the infection progressed the range of chromatographic fractions showing protective capacity was extended to all those containing 7Sgamma2 and 7Sgamma1 immunoglobulins. Fractions enriched for gammaM did not confer protection. Immune serum containing 7Sgamma2a antibodies was able to kill developing parasites after they had left the intestine, and the hepatic postoncospheral forms retained their susceptibility to antibody over the first 5 days of growth. After that time they rapidly became insusceptible to antibody both in vivo and in vitro. Susceptibility to antibody-mediated attack was complement dependent. This appears to be the first time that complement has been demonstrated to play a role in immunity to a helminth infection in vivo. This finding is discussed in relation to the phenomenon of cestode parasite survival in immune animals.


In vitro cultivation of cells from aneuploid human embryos. Initiation of cell lines and longevity of the cultures.

During a cytogenetic study of human spontaneous abortions, attempts were made to initiate cell lines from tissues of embryos with chromosomal anomalies. The rate of success of these attempts and the life-span of the cell cultures is correlated with the development attained by these aneusomic embryos.


Fragmentation of human IgG by a new protease isolated from the basidiomycete Armillaria mellea.

Digestion of human IgG by a new lysine-specific protease, isolated from the basidiomycete Armillaria mellea, produced Fc and Fab fragments similar to those produced by papain digestion of the same molecule. Digestion appeared to be restricted to a single cleavage point within the hinge region of the IgG molecule. Myeloma proteins of IgG1, IgG3 and IgG4 subclasses were found to be digested at an extremely rapid rate whereas IgG2 myeloma proteins appeared to be resistant to digestion by this enzyme.


Paraproteinaemia in inbred chickens.

Sera from seventy chickens of several inbred lines were screened by cellulose acetate electrophoresis for abnormalities of immunoglobulin production. IgG levels in two sera (both from apparently healthy birds) were unusually high. The IgG proteins purified from these two sera were shown, by isoelectric focusing, to be of restricted heterogeneity.


Studies on the role of macrophages in regulation of growth and metastasis of murine chemically induced fibrosarcomas.

Murine solid tumors were shown to contain 9-54% medium to large non-malignant cells bearing receptors for immunoglobulin Fc. These cells rapidly adhered to plastic surfaces, were trypsin-resistant, were capable of phagocytosis of latex particles and were sensitive to the lytic effects of anti-macrophage serum and complement. Purified Fc-receptor-positive cells failed to produce tumors, which strongly suggested that they were macrophages. When tumor-cell suspensions, depleted of macrophages by adherence to plastic surfaces, were injected subcutaneously into normal syngeneic mice, the tumors displayed an increased potential for metastasis. By contrast, control animals which received tumor-cell suspensions containing their normal complement of macrophages invariably developed progressive localized tumors. The survival times of mice infected with macrophage-depleted tumor-cell suspensions were significantly shorter (p less than 0.05) than those for animals inoculated with intact tumor-cell suspensions. These studies confirm the existence of a substantial number of macrophages within progressing syngeneic murine solid tumors and strongly suggest a regulatory role for the macrophages in the growth and metastasis of the tumor.


Inhibition of leukocyte migration in agarose by KCl extracts of human melanoma cell line grown in serum-free medium.

KCl extracts of Melanoma 14, a human melanoma cell line grown in chemically defined serum-free medium, inhibited leukocyte migration in 19/36 (53%) patients with malignant melanoma. Only 4/23 (17%) controls with non-melanoma malignancies and 4/25 (14%) normal subjects with no history of cancer were similarly inhibited. Only 2/27 melanoma patients tested against KCl extracts of normal muscle tissue excised from the donor of Melanoma 14 were significantly inhibited. Patients with Stage I (localized) melanoma and patients with Stage III (generalized) melanoma reacted with roughly equal frequency but the number of patients in each group was too small for meaningful statistical analysis. Leukocytes from the donor of Melanoma 14 were tested in a completely autologous system against extracts of Melanoma 14 tissue culture cells and extracts of autologous muscle and were specifically inhibited by the Melanoma 14 tissue culture extract (Migration Index = 0.67) but not by the extract of normal muscle (Migration Index = 0.96). Only 7/32 (22%) melanoma patients were significantly inhibited by an extract of non-melanoma tumor. These results suggest that melanoma-associated antigens are present in soluble extracts of this tumor line. Such extracts could provide a continuing source of standard melanoma-associated antigens for purification and chemical characterization and for diagnostic and prognostic tests in patients with malignant melanoma.


In vitro synthesis of tumor-specific factors with blocking and antibody-dependent cellular cytotoxicity (ADC) activities.

Spleen cells from BALB/c mice bearing syngeneic sarcomas and from BALB/c mice whose sarcomas had been excised were cultivated in vitro. The culture supernatants were tested for two activities: their ability (1) to supress ("block") specific lymph-node cell-mediated cytotoxic reactions directed against the respective neoplasms; and (2) to induce antibody-dependent cellular cytotoxicity (ADC) specific for the antigens of the respective tumors. Both specific activities, blocking and induction of ADC, were detected in culture supernatants from spleens of tumor-bearing mice, even when repeatedly harvested at intervals over a 7-day period. Supernatants of cultured spleen cells from mice whose sarcomas had been excised 3-4 weeks previously also had ADC but no blocking activity. Supernatnats of cultures treated with inhibitors of protein synthesis lacked both blocking and ADC activities; the inhibitory effect of cycloheximide on these activities, as well as on protein synthesis, was reversible. Factors in the culture supernatants responsible for blocking and for ADC were labelled when the culture were incubated with 14C-leucine. The labelled material was retained by, and could be eluted from, immunoadsorbents for mouse immunoglobulins. In addition, the labelled material bound preferentially to those tumor cells for which specific blocking or ADC activities were observed. The findings indicate that factors responsible for the blocking and ADC phenomena were indeed synthesized by the spleen cells in vitro.


Social determinants of alcohol and marijuana effects: a systematic theory.

Based on the sociological perspective on recreational drug effects, three social determinants are propositionally related to the normal effects of alcohol and marijuana. Effects vary across drugs, users, and situations along an experimental-behavioral dimension termed "effect-orientation." The content of normative expectations toward effects and the interactional characteristics of drug-using situations are conceptualized as direct determinants of effect-orientations. The relative clarity of normative expectations indirectly influences effect-orientations through its relationship to the other two social determinants. The theory stresses the importance of comparative research on the normal uses of alcohol and marijuana.


Attitudes toward alcohol and drug abuse. II. Experimental data, mass media research, and methodological considerations.

This paper will report data concerning the relationship of attitudes and knowledge and will evaluate the effects of various drug and alcohol education programs. The effects of the mass media on drug- and alcohol-related attitudes will also be reviewed, as wll the various methodological problems encountered in the research to date.


Incidence of hepatitis-associated antigen among male narcotic addicts in a drug treatment program.

Since September of 1972, the Drug Dependence Treatment Unit has been screening its narcotic addict patients for the hepatitis-associated antigen (HAA). Among a random population of 243 patients, 2% were positive HAA, a relatively high incidence.


Follow-up of a representative sample of heroin addicts.

The 3.5 year follow-up status of a representative sample of addicts prescribed heroin at London Treatment Centres was ascertained using Home Office records. Fifty-six percent were still receiving opiates from Clinics with 39% still receiving heroin. Six percent were dead, 2% were in prison, while 34% were not know to be using drugs or to be institutionalized. Outcome was significantly related to age with the older sample members being more likely to be prescribed opiates and less likely to be classified as "Off" drugs. This result is in contrast to American reports and is possibly indicative of a perpetuation of dependency encouraged by current treatment methods. Outcome was further partially related to a typology of life styles formulated from date from the original samplw with those who were the most Stable in 1969 being more likely to receive heroin on prescription in 1973, and those classed as Loners and Two-Worlders in the original survey being the most likely to be classed al "Off" drugs by the Home Office.


Demographic characteristics of emergency room admissions of acute drug reactions.

This study investigated a sample of persons treated for acute drug reactions (overdoses) in a hospital emergency room setting to determine the general characteristics of these drug abusers and the incidence of drugs responsible for their admission. Detailed information is provided on the race and sex composition of these drug-abusing patients and comparisons are made with the general population of the area serviced by the hospital. The sample consisted of 506 persons who entered Jackson Memorial Hospital, Miami, Dade County, Florida during January-June 1972. A profile of the typical admission for emergency care of a nonfatal overdose reveals a White female who is 18-24 hears old and who has overdosed on a single legally manufactured and distributed substance, usually a sedative.


Ultrastructure of keloid: an unusual incident involving lepromatous leprosy.

A patient with lepromatous leprosy developed keloids on the dorsum of both arms in response to ulcerations due to acute erythema nodosum leprosum reactions. Electron microscopic examination of the keloidal dermis showed a morphology indicative of increased production of normal collagen fibrils. The greatest cellular changes from normal were in fibroblasts which were enlarged due to increased amounts of rough endoplasmic reticulum and extensive Golgi complexes. Nuclear folds were also evident in these fibroblasts. Some cells, considered to be fibroblasts, were filled with cytoplasmic filaments and contained bizarre shaped nuclei. Mast cells, blood vessels and nerve processes were also present.


Cutaneous effects from rain-tree honeydrew and aphis insects.

Honeydrew and aphis insects which fell from a tree were responsible for paranesthesiae in a woman. Her condition was incorrectly diagnosed as delusions of parasitosis.


Conformational studies on sequential polypeptides Part VI. Structural investigations on (Pro-Leu-Gly)10, (Pro-Leu-Gly)n and (Leu-Pro-Gly)n.

The conformational properties of (Pro-Leu-Gly)10, (Pro-Leu-Gly)n and (Leu-Pro-Gly)n were investigated both in solution and in solid state. By circular dichroism studies it was possible to demonstrate the formation of an ordered collagen-like structure for (Pro-Leu-Gly)n in hexafluroisopropanol-water mixtures and in ethylene glycol; (Leu-Pro-Gly)n assumes an ordered conformation only in ethylene glycol; (Pro-Leu-Gly)10 is unordered under all the conditions studied. X-ray diffraction patterns indicated that (Pro-Leu-Gly)n and (Leu-Pro-Gly)n assume a triple helical structure in solid state. In addition, the investigation of (Pro-Leu-Gly)n strongly suggests that this type of structure is a single chain triple helix. The X-ray patterns of (Pro-Leu-Gly)10 do not allow us to ascertain a collagen or polyproline II-like structure for this decatripeptide.


1H- and 13C-N.M.R. spectra of eledoisin and intermediate oligopeptides.

The 1H- and 13C-n.m.r. spectra of eledoisin and minor oligopeptides were measured and assigned. The proton spectra were interpreted on the basis of homonuclear decoupling, chemical shift criteria and spectra simulation. The information obtained was used in the assignment of the 13C spectrum via heteronuclear 1H-13C. The steric arrangement of proline residue was deduced from the 13C spectrum. Moreover the similarity of the 13C spectrum of eledoisin with that of component oligopeptides suggests that no considerable conformational change occurs in the undecapeptide relative to the component fragments.


Studies on protein folding, unfolding and fluctuations by computer simulation. I. The effect of specific amino acid sequence represented by specific inter-unit interactions.

A lattice model of proteins is introduced. "A protein molecule" is a chain of nown-intersecting units of a given length on the two-dimensional square lattice. The copolymeric character of protein molecules is incorporated into the model in the form of specificities of inter-unit interactions. This model proved most effective for studying the statistical mechanical characteristics of protein folding, unfolding and fluctuations. The specificities of inter-unit interactions are shown to be the primary factors responsible for the all-or-none type transition from native to denatured states of globular proteins. The model has been studied by the Monte Carlo method of Metropolis et al., which is now shown applied to approximately simulating a kinetic process. In the strong limit of the specificity of the inter-unit interaction the native conformation was reached in this method by starting from an extended conformation. The possible generalization and application of this method for finding the native conformation of proteins form their amino sequence are discussed.


The primary structure of ovine interstitial cell stimulating hormone. IV: Disulfide bridges of the beta subunit.

The disulfide linkage of the 12 half-cystine residues in the beta subunit of ovine interstitial cell stimulating hormone has been investigated by enzymic and partial acid hydrolysis of the intact molecule. Results indicate that the disulfide bridges are formed by residues 9-38, 23-72, 26-110, 34-90, 57-88, and 93-100.


The synthesis and biological activity of (165, 182, 189-S-carbamidomethylcysteine)-human growth hormone-(140-191).

The peptide [165, 182, 189-S-carbamidomethylcysteine]-human growth hormone-(140-191) has been synthesized by the solid-phase method. The complement fixation, lactogenic and growth-promoting activities of the synthetic peptide were comparable to that of [165, 182, 189-S-carbamidomethylcysteine]-human growth hormone-(141-191) that was derived from the native hormone.


The ophthalmologist's office: planning and practice. Office forms.

For each new office problem that occurs, some antidote may be devised using an office form. This is an area of office management that really taxes the ingenuity of the young ophthalmologist; however, if he or she keeps the concepts of office efficiency and patient enlightenment uppermost in mind, the resulting office forms will justify their creation many times over.


The ophthalmologist's office: planning and practice. Getting paid and completing insurance forms.

This chapter describes a systematic approach to the art of collection for services rendered, based primarily on a pay-as-you-go philosophy. A system of internal office-controlled billing, timed so that the statements reach the patients on the last day of the billing month instead of the first day of the following month, unequivocally works more smoothly in the author's office than external computerized billing did. Suggestions to effect and maintain a collection ratio of at least 95 percent have been enumerated. The use of a new statement-and-insurance form facilitates billing, keeping ahead of insurance applications for patients, and advising the front office of other internal tasks to be performed. Finally, the importance of the general ledger, under the supervision of the ophthalmologist's accountant and in conjunction with a control procedure (employing the daily master appointment page attached to the ophthalmologist's personal worksheet) is stressed, in order to safeguard the physician's revenue.


What a bank can do for the ophthalmologist.

The selection of a bank is the key to personal and professional finance. In this world of specialization, it is advisable to seek a banker who can assist one with not only the routine banking functions but also with credit accommodations and financial planning which will result in both the successful operation of a profession and the achieving of a sound estate plan.


The ophthalmologist's office: planning and practice. Life insurance.

Life insurance is a necessary part of life. There are many types of insurance, with varying costs, so each individual situation calls for a carefully tailored policy, modified periodically according to one's changing needs. To  do this requires some basic knowledge on the part of the purchaser, plus the coordinated help of a competent insurance advisor, lawyer, and accountant. The medical prescription a physician writes first requires an adequate examination and workup of the patient, following which it is written for a specific purpose. In the same way, the life insurance plan selected by an individual should be decided upon only after a complete history and examination of that person and his or her needs.


The ophthalmologist's office: planning and practice. Property and casualty insurance.

This chapter is primarily an overview of the physician's need for insurance; of necessity, it is not a detailed examination. Each individual physician should review personal insurance needs thoroughly with a reputable insurance agent, handling property and casualty insurance, and a life insurance agent with respect to need for life insurance and accident, sickness, and medical insurance. As mentioned earlier in this chapter, an attorney should review any lease for office space or any lease that the physician might have with tenants of a building that he or she owns. The attorney can advise as to one's liability exposure, and the professional insurance agent then can provide the necessary insurance program to cover exposure to that risk. One final comment. Insurance policies are imortant papers: They should always be protected.


The ophthalmologist's office: planning and practice. Type of practice.

It vitally concerns the prospective new member of a group (single or multiple) to retain a knowledgeable attorney who should review the contract with at least the six points described at the beginning of this chapter uppermost in mind. No verbal or written commitment ever should be made until this has been done.


The ophthalmologist's office: planning and practice. Creation of a management team.

The ophthalmologist's management team might be likened to an equilateral triangle, the base of which consists of the personal banker and the two other parts being attorney and accountant. The equal and integrated efforts of these individuals strongly insure the ophthalmologist's future financial and professional success.


The ophthalmologist's office: planning and practice. Selection of an office site.

The selection of the office site constitutes one of the most important steps in the creation of the young ophthalmologist's practice. The location of the office has important implications for the physician and his or her family and future patients. By selecting the correct type of building in which he or she can efficiently utilize an adequate amount of space, the young practitioner virtually insures future economic success and at the same time creates an office environment that will prove pleasing to patients, staff, and, most important, the ophthalmologist.


The ophthalmologist's office: planning and practice. Equipment.

Equipping the office deserves the young ophthalmologist's utmost attention. A qualified designer and decorator will make a tremendous difference in creating the most comfortable and efficient office for the individual. Consultation with the office management team will answer questions concerning whether to lease or to buy outright all of the equipment described. The beginning practitioner should always look for the best way to finance outright purchases of equipment, if that be the case. Finally, all used equipment should be checked by an expert mechanic before purchase.


The ophthalmologist's office: planning and practice. Telephone requirements.

A well-designed and properly installed office communications system, combined with courteous and attentive telephone manners, serves as a most important basic building block in the creation of a successful office practice. The necessity for courtesy to callers applies not only to the office staff but also to the personnel handling the telephone when the office closes.


The ophthalmologist's office: planning and practice. Location of practice.

A majority of positive responses to the questions posed in this chapter offers the comforting prospect of a wise and potentially successful decision in selecting the location of a practice. (Local Chambers of Commerce usually offer very useful information in answer to the nonmedical questions.) Finally, it should be remembered that this decision is a joint one-the ophthalmologist's spouse and children (if they are old enough) should be involved as much as possible. If they are happy, the intangible rewards will be inestimable.


The ophthalmologist's office: planning and practice. Staffing.

By seeking top-flight office personnel and then offering attractive salaries and fringe benefits, systematically and selectively screening available applicants, and properly training and indoctrinating them in office policies, task analysis, and performance, the young ophthalmologist will assemble the most useful and compatible office staff, thereby making his or her professional life most productive and pleasant.


The ophthalmologist's office: planning and practice. Effective patient scheduling.

Effective patient scheduling, a most important building block in the creation of any successful practice, can best be accomplished by (1) devising a specially designed appointment book to suit the individual needs of each ophthalmologist; (2) thorough education of the telephone receptionist in the working habits of the ophthalmologist, in the ability to evaluate ocular emergencies, in the screening of personal calls, and in the importance of "break" time for the doctor; and (3) formulation of methods to reduce lost time because of irresponsible patients.


The ophthalmologist's office: planning and practice. Patient records and filing systems.

Suggestions and examples of the components of patient charts have been offered for the most efficient office system and for the greatest protection of the ophthalmologist against malpractice charges. Emphasis has been placed on the alphabetical system of filing, the need for well-designed filing cabinets, and measures to reduce the incidence of misplacing and losing patient charts.


Solute excretion during intravenous urography. A comparison of sodium iothalamate and sodium iocarmate (iothalamate dimer).

Sodium iothalamate and sodium iocarmate (iothalamate dimer) were compared as urographic agents. The two agents were administered intravenously to dogs at a dose level of 600 mg I/kg. The concentrations and outputs of major urinary solutes and injected solutes were measured to define the differences in diuretic effect of the two agents. The urinary output and concentration of iodine with each agent were also compared. The diuresis with iocarmate was lower. It was apparent that the lower diuresis and higher urinary iodine concentration with iocarmate was due to the lower osmotic activity per iodine atom obtained with this agent.


Spectrofluorometric analysis of illicit drug samples, employing a corrected excitation spectrofluorometer.

Spectrofluorometry, because of its high sensitivity, has developed into one of the most useful analytical methods available to the forensic chemist for certain ilicit drug samples encountered in small amounts. The corrected excitation spectrofluorometer adds to the usefulness of this technique by generating more reproducible results with greater sensitivity. The excitation spectra are in better agreement with absorption spectra, and the need to recalibrate constantly with standard solutions in order to perform quantitative analysis can be minimized. Lysergic acid diethylamide and a fluorophore of morphine related drugs were examined employing a corrected excitation spectrofluorometer. Data is presented substantiating the advantages of a corrected instrument.


[Clinical picture and roentgen therapy of lip carcinomas].

204 patients with lip cancer (squamous cell carcinoma and basal cell carcinoma) were irradiated with soft x-ray and cobalt-radiation respectively after histological examination of the tumor. Available observations were supplied by 190 patients. Distribution according to age and histology, the size of the tumor, as well as the therapeutic results and the recurrence rates are reported. 96,6% of the tumors which showed no metastases at the beginning of the treatment remained recurrence-free after radiation. Early diagnosis, the necessity of treatment and the problem of prophylaxis are emphasized.


[Porphyria cutanea tarda and blood-sugar-suppressing derivatives of sulfonylurea].

A screening test for urinary porphyrin excretion was performed amound 1433 diabetes patients (552 males and 881 females). In three patients (0.21)% the diagnosis of porphyria cutanea tarda was ascertained. In spite of the increasing usage of sulfonylurea antidiabetic drugs, previously reported as potential porphyria-inducing agents, the authors could not observe an increased number of porphyria cases among the diabetics compared to the proportions in similar groups examined 10-12 years ago. The sulfonylurea Oradian was the likely etiopathogenic factor in only one out of three patients. The above mentioned observations do not speak in favour of independent etiological porphyrinogenic influence of antidiabetic sulfonylurea drugs.


[Radioimmunologic determination of total IgE and allergen-specific IgE-antibodies in diffuse neurodermitis].

Total IgE levels in sera of 165 patients with atopic dermatitis and 79 patients with dermatoses as well as normal control patients were determined by radioimmunoassay (Phadebas, Pharmacia). Although the mean value for patients with atopic dermatitis was found far above the mean value for normal controls, 38% of patients showed total IgE serum levels within the normal range. Highest IgE serum levels were observed in patients with the generalized form of the disease and in patients with asthma and allergic rhinitis. No direct correlation however, to severity of disease could be found. In a series of 50 patients prick tests were compared to total IgE serum levels and to levels of allergen specific antibodies determined by radioallergosorbent-test (RAST). Extracts of grass pollens and of animal dandruff were used. There was complete agreement between results of skin testing and RAST in at least 80%. While cross reactions were common with grass pollen extracts in RAST, there was no cross-over with animal dandruff. No correlation was found between titer of allergen specific antibody and severity of skin lesions. IgE specific antibody could be detected in 48% of patients with normal total IgE serum levels and in 82% of patients with elevated values.


Cardiovascular effects of ionic monomeric, ionic dimeric and non-ionic contrast media. Effects in animals on myocardial contractile force, pulmonary and aortic blood pressure and aortic endothelium.

Three different types of contrast media, monomeric ionic, dimeric ionic and monomeric non-ionic, were tested and compared concerning their toxicity on three experimental models: I. Pulmonary artery and aortic pressure after contrast medium injection into the right atrium in rabbits: II. Ventricular contractile force and heart rate after perfusion of the coronary arteries on the isolated rabbit heart: III. Aortic endothelium of rats. Non-ionic contrast medium was, in all three experiments, less toxic than monomeric ionic; thus it caused less rise in pulmonary artery pressure (I) and caused less reduction in ventricular contractile force and heart rate (II) and caused less damage on aortic endothelium of rats (III). The non-ionic contrast medium also gave less toxic reaction in two (I and II) of the three models compared to the dimericionic contrast medium. In experimental model III there was no difference between these two agents. Also, the dimeric ionic contrast medium caused less toxic reactions in all three models than the monomeric ionic contrast medium.


The effect of decreased renal artery perfusion pressure on intrarenal hemodynamics in the dog.

The role of decreased renal artery perfusion pressure in redistribution of renal cortical blood flow during acute hemorrhagic hypotension is unclear. Renal artery hypotension was produced in intact dogs by an intra-aortic balloon catheter placed cephalad to the origins of the renal arteries. Renal cortical perfusion was assessed using selective renal magnification arteriography, isotopically labeled microspheres, and xenon-133 washout. After 60 minutes of decreased renal artery perfusion pressure (40 to 50 mm Hg), no changes were noted in renal cortical perfusion arteriographically. Microsphaere distribution to each cortical zone was unchanged, despite a marked decrease in total renal blood flow and in flow to each zone. 133Xe washout curves permitted two interpretations: Either redistribution of blood flow away from the cortex occurred, or parallel decrease in flow to each zone occurred without redistribution. Results indicate decreased renal artery perfusion pressure does not cause redistribution of renal cortical blood flow in our model.


Angiographic patterns in experimental obstruction of the small bowel.

Mechanical obstruction of the small intestine was induced in 79 rabbits. Ligation and/or fixation of an intestinal loop with sutures was performed in order to produce simple obstruction, strangulation, intussusception and volvulus. The obstructed loop and the adjacent segments of the bowel were examined with microscopic, microangiographic and angiographic methods at fixed time intervals of 6, 12, 24 and 48 hours. Dynamics of arterial changes in the intestinal wall and mesentery were investigated. Angiographic patterns of obstruction in the exteriorized loop of a living animal are described. These findings may be of value in evaluating clinical cases.


[Familial subungual pterygias].

In two patients (mother and daughter subungual pterygia were seen on the fingers of both hands. The abnormalities were congenital and painful. A disproportional extension of the nail bed epithelium with dislocation of the hyponychiuum is the suggested cause of this entity. No useful therapy was found.


Degenerative disease of the sacroiliac joint.

Analysis of 46 sacroiliac joints removed in toto at random during routine autopsies was undertaken to define the pathologic and radiographic alterations of this joint in middle-aged and elderly patients. Each joint was sectioned, photographed and radiographed and large microscopic slides were prepared. Sacroiliac osteoarthrosis resulted in progressive cartilage degeneration, particularly on the ilial side of the joint, with eventual cartilaginous fusion. Para-articular bony ankylosis was produced by bridging osteophytes on the anterior and inferior surfaces. Sacroiliac intra-articular bony ankylosis was confined to cadavers with ankylosing spondylitis. In some patients radiographic differentiation of osteoarthrosis and ankylosing spondylitis may require tomography.


Ultrastructure of endocrine cells in metaplastic epithelium of human gall bladder.

Two endocrine cell types were found in the metaplastic epithelium of gall bladders removed for gall stones. The endocrine cell type I resembled the EC (enterochromaffin) cell of the normal stomach mucosa. The homogeneous and electron-dense secretory granules were variable in size and shape and mainly located in the sub-nuclear cytoplasm. The endocrine cell type II was similar to the ECL (enterochromaffin-like) cell of the human stomach. The secretory granules were almost exclusively present in a subnuclear location, and were round and homogeneous in size. The secretory material was slightly granular and often there was a clear zone (halo) between the granule core and the limiting membrane. A rich network of microfilaments in the cytoplasm, especially around the nucleus, was typical of the type II endocrine cell. Both cell types were closely related to the basement membrane and the capillaries underneath.


Megakaryocytopoiesis in the liver of the developing opossum (Didelphis virginiana).

The development of hepatic megakaryocytes has been examined in the livers of 35 young opossums at four different stages of postnatal development. Megakaryocytopoiesis is carried out within the sinusoidals and there appears to be a close relationship between the young megakaryocytes and the sinusoid lining cells. Megakaryocytes in the opossum are relatively small and lack the degree of nuclear complexity seen in other species. Both the nucleus and the cytoplasm undergo sequential maturational changes but, in the newborn especially, these sequences are not necessarily interrelated and there is a rapid cytoplasmic differentiation to provide for early platelet release. A scheme for the maturation of the hepatic megakaryocytes is presented.


The development of human digital tendons.

The development of human digital flexor and extensor tendons from 40 days to 112 days of gestation is described. The differentiation of the cell, the formation of collagen fibrils, and their organization into a relatively complex tendon organ are described. This word was supported by a grant from the Graduate Research Fund of the University of Washington. (Materials were obtained from the laboratory for human embryos which is supported by N.I.H. Grant no. HD00836.) We would like to thank Mrs Bea Watts for secretarial assistance.


'Ambidexterity' in bat wings as evidenced by bone weight.

1. Comparable right and left wing bones of three species of bats failed to demonstrate one-sided dominance, although such dominance is widespread in tetrapods. 2. When similar units are compared, some of the bones from one side are heavier, some are lighter, than those from the other side. This appears to represent a compensatory mechanism for achieving balanced weight and propulsion. 3. The criterion used by Dogra & Singh (1971) for deciding whether or not a difference exists between comparable units (i.e. that an observed difference in weight is 'real' if the difference is at least one per cent of the weight of the greater element) is not statistically valid in the three  species of bats used in this study. Sole use of this criterion to determine one-sided dominance can therefore be misleading.


The time-course of changes in mucosal architecture and epithelial cell production and cell shedding in the small intestine of the rat fed after fasting.

Rats were starved for 3 days, then either allowed access to food or continued in starvation. The following measurements on the upper jejunum were made on groups of refed and starved rats at nine time intervals after refeeding: villus height, crypt depth, crypt/villus ration, rate of cell production per crypt, and number of epithelial cells shed per villus in 5 minutes. Villus height increased 2 hours after refeeding, while crypt depth changed less dramatically. Crypt/villus ratio was unchanged. The number of shed epithelial cells per villus was reduced below the starved level for 4 hours after refeeding, and did not rise significantly above the starved level until 9 hours; the rate of cell production was not significantly increased until 12 hours after refeeding. No evidence for a reserve of cells in G2 was found, and the 3 hour lag between the rise in cell shedding and the increase in cell production would probably not give enough time for cells in G1 to pass through S and G2. It is concluded that these observations do not support the hypothesis that increased cell shedding from the top of the villus stimulates increased cell production in the crypts of Lieberkuhn.


New observations of rat airway epithelium: a quantitative and electron microscopic study.

Epithelial thickness, depth of the ciliary layer and concentration of cells has been estimated at 5 levels of the rat airway (3 extrapulmonary and 2 intrapulmonary) and the ultrastructure of the cells described. Extrapulmonary airways have a pseudostratified epithelium, intrapulmonary airways a simple one. The epithelium thins progressively from upper to lower trachea while the epithelium of the lower trachea is thicker than at more peripheral airway levels, all of which are similar. The depth of the ciliary layer decreases peripherally. By electron microscopy 10 cell types could be identified - 8 epithelial and 2 'migratory'. A cell type not described previously has been found that resembles the serous cells of the submucosal glands. The salient features of each cell type are described. The upper trachea has a concentration of cells significantly higher than elsewhere, while the remaining four airway levels have about 230 cells per 10 high power fields (1-8 mm length epithelium). Ciliated cells are sparse proximally and increase in number progressively toward the periphery, while basal and migratory cells are most frequent proximally. At all levels of the airway, between 40% and 50% of cells are non-ciliated. In the upper trachea the most frequent cell type was the 'intermediate', elsewhere the 'epithelial serous' cell. Goblet cells were few at all levels, amounting to less than 1% of the total counted. The Clara cell was not restricted to the terminal bronchioles but was found as far proximally as the hilum.


Development and structure of the extra-embryonic membranes of the ferret. A light microscopic and ultrastructural study.

Light and electron microscopic observations on the development and structure of the extra-embryonic membranes of the ferret are described. By day 16 of pregnancy trophoblastic villi consisting of a cytotrophoblastic core with a peripherally located phagocytic syncytiotrophoblast have penetrated deeply into the endometrium. During its invasion the syncytiotrophoblast removes endometrial glandular cells and some of the adjacent stromal tissue. The maternal blood vessels remain intact and eventually become surrounded by the syncytiotrophoblast. A marked hypertrophy of the maternal capillary endothelium then begine. By day 28 the maternal capillary endothelial cells attain their maximum height. The cytoplasm of these cells contains numerous cisternae of rough endoplasmic reticulum and a well-developed Golgi apparatus, features which are typical of protein-secreting cells. The maternal blood vessels are separated from the syncytiotrophoblast by a thick layer of amorphous material which stains positively with PAS. Alcian blue staining in the presence of critical concentrations of magnesium chloride indicates the presence of both sulphated and carboxylated acid mucopolysaccharides. It may be that the amorphous material contributes significantly to the nutritional requirements of the developing fetus. Invaginations of the syncytiotrophoblast plasma membrane facing this amorphous layer are often seen. Coated vesicles and substances in contact with the outer surface of the membrane are therefore likely to be endocytozed. The acid phosphatase in the syncytiotrophoblast is consistent with the presence of lysosomes and catabolic function. Regions of paraplacental cellular trophoblast which lie in close association with the endometrium, but do not penetrate it, appear to specialize in endocytosis. The haemophagus organ, which is located at the antimesometrial pole, is the site of rupture of maternal blood vessels, and the extravasated blood lies in close association with the chorio-allantoic membrane. The maternal blood cells ingested by the trophoblast in this area are presumably an important source of iron for the embryo. The cellular trophoblast in the paraplacental regions is well equipped with hydrolytic enzymes, as shown by histochemical tests for acid phosphatase. It seems likely that these regions are concerned with embryotrophic endocytotic nutrition supplementing endothelio-chorial nutrition.


Developmental origin and early differentiation of retinal Müller cells in mice.

During the prenatal development of the retina in mice Müller cells at the initial stage of differentiation show a high level of histochemically detectable non-specific esterase activity. These are the first of the retinal cell types to differentiate and appear at the 11th day of gestation along the vitreal border in the central retina. As development proceeds they appear in more peripheral areas and their perikarya migrate outwardly and become scattered throughout the depth of the retina. Appearance of presumptive Müller cells is followed by rapid growth of the retina and differentiation of the inner retinal layers. With the progress of histogenesis from the central to the peripheral areas the esterase activity in the Müller cells gradually diminishes. The possible significance of early differentiation of Müller cells in promoting growth and histogenesis of retina is discussed.


The localization of acetylcholinesterase in the locus coeruleus of the normal rat and after 6-hydroxydopamine treatment.

The locus coerulus is a densely packed group of neurons in the floor of the fourth ventricle, and is the largest aggregate of noradrenaline-containing cells in the mammalian brain. The distribution within the locus of acetylcholinesterase (AChE), which is present in high concentration, has been studied at light and electron microscope level, both in normal rats and in ones treated with 6-hydroxydopamine. Neuronal enzyme activity is entirely intracellular and mainly concentrated in stacks of ER which occupy much of the cell cytoplasm. There are no indications of a cholinergic input. After 6-hydroxydopamine treatment extensive cell death occurs and AChE activity virtually disappears. A majority of the many blood vessels in the locus also stain strongly for AChE, unlike those present in most other areas of the rat brain. The locus coeruleus therefore represents an area of the rat brain with a high content of AChE, but no evidence of a cholinergic mechanism. Some possible explanations for this anomalous presence of AChE are briefly discussed.


Nanaomycins, new antibiotics produced by a strain of Streptomyces. I. Taxonomy, isolation, characterization and biological properties.

Nanomycins are new antibiotics produced by the strain OS-3966 which was designated Streptomyces rosa var. notoensis. Nanomycins A and B were isolated from the culture filtrate by extraction with organic solvent and silica gel chromatography. The physical and chemical properties suggest that nanaomycins A and B are quinone-related compounds having the molecular formulae, C16H14O6 and C16H16O7, respectively. Nanaomycins A and B inhibit mainly mycoplasmas, fungi and Gram-positive bacteria. The acute toxicities (LD50, ip) of nanaomycins A and B in mice are 28.2 and 169 mg/kg, respectively.


Nanomycins, new antibiotics produced by a strain of Streptomyces. II. Structure and biosynthesis.

Evidence is put forward which describes the structure and stereochemistry of new antibiotics, nanaomycins A and B, as I and V, respectively. In order to study biosynthesis and to determine the position of the hydroxyl group in the naphthoquinone moiety, a feeding experiment with 1-13C-acetate was effectively carried out. Nanaomycins A and B were found to be synthesized from acetate via a polyketide by Streptomyces rosa var. notoensis.


Structure of pyridindolol, inhibitor of beta-galactosidase.

Pyridindolol is a product of a streptomyces and exhibits inhibitory activity against bovine liver beta-galactosidase. The structure of pyridindilol, 1-[1(R), 2-dihydroxyethyl]-3-hydroxymethyl-9H-pyrido[3,4-b] indole, has been established by spectroscopic analyses and an X-ray structure determination.


Stimulatory effect of amphotericin B methyl ester on the grwoth of L-M and Vero cells.

The chemically modified polyene macrolide antibiotic, amphotericin B methyl ester (AME), exhibited a concentration-dependent growth stimulatory effect on established lines of mouse (L-M) and monkey (Vero) cells. Stimulation was indicated by increases in growth rate, and in the enhanced synthesis of DNA and RNA. In contrast, the parental antibiotic amphotericin B and the desoxycholate complex of amphotericin B, FungizoneR, did not elicit a similar proliferative response in L-M or Vero cells. AME was not growth-promoting toward low passage strains of mouse (PMK 6) and monkey cells (MGK 8).


Van Nes rotational osteotomy for treatment of proximal femoral focal deficiency and congenital short femur.

The results of twenty Van Nes rotational osteotomies for unilateral proximal femoral focal deficiency and congenital short femur were analyzed after follow-ups of two to eight years. Assessed on the basis of prosthetic function, the results were good in ten, fair in six, and poor in four. Twelve patients required a rerotation procedure, six of them twice, because of postoperative derotation. Appropriate leg-length discrepancy to place the ankle, converted to the knee, at the right level, as well as normal ankle and foot motion and muscle power, are prerequisites to the procedure, which should be deferred until the child is about twelve years old to avoid prolonged hospitalization for rerotation and gait training.


Acetabular disruption and central fracture-dislocation of the hip. A long-term study.

Displaced acetabular fractures are serious injuries often resulting in permanent disability. Fifty-five patients with fifty-six such injuries seen at the Campbell Clinic between 1927 and 1970 had either central dislocation with or without fracture of the weightbearing dome, or acetabular disruption usually associated with posterior displacement of the hip. After an average follow-up of 8.6 years, 56 per cent of those treated without surgery had good or satisfactory results compared with 54 per cent good or satisfactory results in those treated surgically. Patients with displaced fractures of the acetabular dome not reduced by manipulation and traction should be considered candidates for open reduction.


Arthrography for the assessment of pain after total hip replacement. A comparison of arthrographic findings in patients with and without pain.

Arthrography in twenty-five painful hips of twenty-one patients after total hip replacement and in fifty-three asymptomatic hips of forty-two patients after this procedure showed that arthrographic evidence of loosening was not always associated with pain. More than one-fifth of the asymptomatic hips had arthrographic evidence of loosening. Furthermore, the loosening shown by arthrogram could be confirmed in only seven of twelve hips that were subsequently explored. In addition, there was no apparent relationship between arthrographic loosening and the presence of a Trendelenburg sign. This study casts doubt on the value of an arthrogram in the diagnosis of the cause of pain after total hip replacement.


The early management of open joint injuries. A prospective study of one hundred and forty patients.

A study of open joint injuries treated at the Los Angeles County-University of Southern California Medical Center from July 1969 through July 1973 showed that the vast majority of these injuries were at the knee. Three types of injury were identified: those associated with fractures, injuries without fracture, and gunshot  wounds. All patients were treated with antibiotics, surgical débridement and irrigation, and installation of polyethylene tubes into the joint as a system of postoperative closed irrigation. The over-all infection rate was 2.1 per cent. The results of treatment indicate that the irrigation system can be a source of contamination. Our recommended treatment for open wounds in joints is wide-spectrum systemic antibiotics, surgical débridement, irrigation of the joint and soft tissues, and primary closure. Prolonged suction-irrigation treatment postoperatively should only be done for specific indications: excessive contamination or excessive tissue damage when the wound to the joint should be closed primarily.


Galeazzi fracture-dislocations.

Among 125 patients with the Galeazzi-type fracture-dislocation of the forearm, there were fourteen children and eighty-six adults with the classic Galeazzi lesion, and twenty-five patients with a special type -- fracture of both bones and dislocation of the distal radio-ulnar joint. Conservative management was successful only in children. In adults this method resulted in failure in 80 per cent of cases. The results of operative treatment were much better. The fracture fragments of the radius and the dislocation of the radio-ulnar joint in this complex injury are very unstable, especially in the lesion with fractures of the radius and ulna, and it appears that rigid internal fixation is necessary for the dislocation as well as the fracture. With combined fixation over half of the results were excellent.


Recurrent dislocation of the elbow.

Recurrent dislocation of the elbow resulted from laxity of the lateral capsule and collateral ligament in four patients. An intra-articular lesion was usually also present. Elbow arthrotomy for removal of loose bodies and repair of the lateral capsuloligamentous structures are thought to offer an excellent prognosis for satisfactory relief from symptoms of recurrent dislocation. More complicated techniques, such as bone blocks or tendon transfers, are believed to be less effective and unnecessary.


Prevention and treatment of non-union of slightly displaced fractures of the lateral humeral condyle in children. An end-result study.

In a ten-year study of the healing responses of thirty-one children with fresh fractures of the lateral condyle of the humerus with less than four millimeters of displacement, there were three patterns of healing. Forty-nine per cent healed rapidly in six weeks with abundant callus and periosteal new bone. Thirty-eight per cent healed slowly over eight to twelve weeks, mostly by endosteal union with little callus. Thirteen per cent had progressive displacement of the fragment in the plaster cast and required surgery to prevent non-union. Those fractures that healed had two millimeters or less of displacement of the fragment initially. Those that did not heal had an average of three millimeters of initial displacement. Established non-unions in good position that were symptomatic while the elbow was still immature were salvaged by bone-grafting, sparing the physis of the condylar fragment. The fragment united and grew with the elbow to maturity, producing an excellent end result on long-term follow-up. When the physeal plate of the ununited condylar fragment was absent, the fragment could not grow with the elbow and the result of surgery was less satisfactory.


Fracture of the capitulum humeri.

Fourteen patients with fracture of the capitulum of the humerus were treated, ten by excision of a large fragment or multiple small fragments. Their results were superior to those in patients treated either by closed reduction or by open reduction and fixation. Nine had good to excellent retention of elbow motion, six had no pain, and three had minimum pain. None of the ten had valgus deformity or instability.


Segmental resection for chondrosarcoma.

Specific anatomical and pathological criteria for resectability of so-called central chondrosarcoma of the extremities were set forth and a method of treatment based on autoclaving the segment and surrounding it with massive amounts of fresh autogenous cancellous bone was used in eight patients. Follow-up ranged from 3.2 to 13.5 years. The advantages of the method are: ease of procurement of bone graft, absence of storage and measurement problems, and lack of need for rigid immobilization. No secondary procedures were required because of fracture, resorption, or infection.


Progressive kyphosis following solid anterior spine fusion in children with tuberculosis of the spine. A long-term study.

Two hundred and forty-one consecutive anterior spine fusions for tuberculosis were reviewed to determine how often late progressive kyphosis occurred because of disproportionate growth of the posterior and anterior elements. Three of thirty-one patients with objective roentgenographic evidence of solid anterior fusion had an increase in kyphosis. Two of these had findings suggestive of growth retardation of the anterior ring epiphysis above the fusion mass. Posterior-element overgrowth in the third patient could not be excluded as a cause.


Impotence after fractures of the pelvis.

Sexual impotence after an injury causing a fracture of the pelvis occurred in sixteen of ninety male patients. Three men of fifty-nine had this complication without having an associated injury to the urethra, but impotence was more commonly associated with urethral injury (thirteen of thirty-one cases). Litigation did not seem to be associated with the problem.


Patella alta and patella infera. Their etiological role in patellar dislocation, chondromalacia, and apophysitis of the tibial tubercle.

The Insall-Salvati method of assessing the position of the patella was applied to four groups of patients:normal patients, and those with dislocation of the patella, chondromalacia of the patella, and apophysitis of the tibial tubercle. The ratio of patellar length to tendon length was 1.0 in the normal patients, 0.8 in the patients with dislocations, 0.86 in those with chondromalacia, and 1.2 in those with apophysitis of the tibial tubercle. Patella alta may be an important cause of dislocating patella and of chondromalacia patellae. The significance of the patella infera found in the Osgood-Schlatter lesion may be one of either cause or effect.


Meniscectomy and chondromalacia of the femoral condyle.

One hundred and fifty-four knees with 161 torn menisci were examined with the arthroscope immediately before meniscectomy. The incidence of early degenerative arthritis (chondromalacia) of the femoral condyle was correlated with the age of the patient, the interval between injury and surgery, and the type of meniscal lesion. The incidence of condylar chondromalacia was significantly higher in patients over the age of thirty (p less than 0.01) and in those with a history longer than three months (p less than 0.05). Posterior horn tears were associated with the highest incidence of degenerative changes, but were also associated with a longer history and with older patients. Attention is drawn to the adverse effect of damaged menisci on condylar articular cartilage, and a plea is made for early diagnosis and removal of damaged menisci.


The functional treatment of pyogenic arthritis of the adult knee.

A method of treatment of pyogenic arthritis of the adult knee employing wide open arthrotomy and early active motion, as well as synovectomy in some knees, was used in thirty-four patients with pyogenic arthritis of the knee. Of these patients, sixteen had a good result, twelve had a fair result, and six had a poor result. This method of treatment was used as a salvage procedure in most of the patients, but may have more general application in the treatment of pyogenic arthritis of the knee.


Experimental replacement of the anterior cruciate ligament. A histological and microradiographic study.

In each of four dogs, teno-osseous autogenous grafts were used to reconstruct the anterior cruciate ligament. The transplanted strips first underwent ischemia and cellular death, with necrosis of both bone and tendon. Ingrowth of tissues then occurred rapidly, but complete incorporation of the tendon or the bone did not occur at one year. However, the tunnel-to transplant bone was functional and provided sufficient stability to the knee so that disruption of the reconstructed anterior cruciate ligament did not occur.


The trochanteric approach to the hip for prosthetic replacement.

A new lateral operative approach to the hip was used for the insertion of 222 total hip prostheses for arthritis. The trochanter is cut off more deeply and more vertically than hitherto, with all of its muscle attachments, including the vastus lateralis, intact. The inclusion of the vastus lateralis stabilizes the fragment by counteracting the gluteus medius; together they generate an inward-acting muscle force on the fragment. Reattachment was by wire in 120 cases and directly to the femoral implant by bolt and graft in 102 cases. In the bolt attachment operation a new type of femoral component was used in conjunction with a variable-thickness bone graft. The method of trochanteric attachment was thought to contribute to the quality of bone repair by eliminating tensile forces and generating compressive forces. In all patients early mobilization and full weight-bearing were encouraged.


On the natural history of hemophilic pseudotumor.

Seven cases of hemophilic pseudotumor were followed for at least ten years. Apparently adequate and early substitution therapy for bleeding in muscles and skeleton will prevent the occurrence of such pseudotumors. Conservative treatment of established pseudotumors with substitution therapy at bleeding symptoms is advocated, but in the event of continued growth of the pseudotumor and threatened perforation, radical extirpation may have to be done.


Surgery in hemophilic patients.

Surgery in hemophilic patients was performed under proper factor-replacement therapy, and a wide variety of orthopaedic procedures (twenty-six in seventeen patients) were done with good results. There were no complications in any of the patients since the advent of concentrates in 1966. Multiple procedures under one anesthetic are recommended because the complications associated with repeated administration of blood substitutes are minimized.


Coccidioidal arthritis and its treatment -- 1975.

The clinical course of disseminated coccidioidomycosis is highly variable. Neither spontaneous cure nor spontaneous ankylosis has ever been demonstrated in an adult with the disease in one or more disseminated articular foci. Coccidioidomycotic arthritis may fluctuate in activity, and may be compatible with years of limited function and moderate morbidity. Amputation as well as arthrodesis accompanied by adequate excision of diseased tissue are generally reliable methods of treatment of infected joints, but the decision whether or not to "cover" such patients with systemic doses of amphotericin is still difficult, and the roles of synovectomy and topical amphotericin remain to be determined.


Structural changes in the membrane of vero cells infected with a paramyxovirus.

Vero cells productively infected with the Halle strain of measles virus have been studied by means of surface replication, freeze-fracturing, and surface labeling with horseradish peroxidase-measles antibody conjugate in order to examine changes in the structure of the cell membrane during viral maturation. Early in infection, the surfaces of infected cells are embossed by scattered groups of twisted strands, and diffuse patches of label for viral antigens cover regions marked by these strands. At later stages, when numerous nucleocapsids become aligned under the plasmalemmal strands, the strands increase in number and width and become more convoluted. At this stage, label for viral antigens on the surface of the cell membrane is organized into stripes lying on the crests of strands. Finally, regions of the membrane displaying twisted strands protrude to form ridges or bulges, and the freeze-fractured membrane surrounding these protrusions is characterized by an abundance of particles small than those found on the rest of the cell membrane. The fractured membranes of viral buds are continuous sheets of these small particles, and the spacing between both nucleocapsids and stripes of surface antigen in buds is less than in the surrounding cell membrane. Detached virus is covered with a continuous layer of viral antigen, has unusually large but no small particles on its membrane surfaces exposed by freeze-fracturing, and no longer has nucleocapsids aligned under its surface. Thus, surface antigens, membrane particles, and nucleocapsids attached to the cell membrane are mobile within the plane of the membrane during viral maturation. All three move simutaneously in preparation for viral budding.


Gametic differentiation in Chlamydomonas reinhardtii. I. Production of gametes and their fine structure.

Gametogenesis in Chlamydomonas reinhardtii has been studied in mating-type plus cells utilizing several different culture conditions, all of which are shown to depend on the depletion of nitrogen from the medium, and the fine structure of gametes prepared under these conditions has been compared by using thin sections of fixed materials. We document alterations in ribosome levels, in chromatin morphology, in starch levels, in the organization of chloroplast membranes, and in the appearance of nuclear envelope and endoplasmic reticulum membranes during gametogenesis. We also noted the acquisition of two new organelles: a mating structure (Friedman, L., A. L. Colwin, and L. H. Colwin. 1968. j. cell Sci. 3:115-128; goodenough, U. W., and R. L. Weiss. 1975. J. Cell Biol. 67:623-637), and Golgi-derived vesicles containing a homogeneous material. We chart the time course of these morphological changes during synchronous gametogenesis. We note that many of these changes may represent adjustments to nitrogen starvation rather than direct features of gametic differentiation, and we also document that cells can differentiate so that they survive conditions of nitrogen starvation for many weeks after they become gametes. We conclude that metabolic alterations, the acquisition of mating ability, and the preparation for long-term survival are all elicited in this organism by nitrogen withdrawal, and we discuss how the various structural alterations observed in this study may relate to these three interrelated avenues of cellular differentiation.


Gametic differentiation in Chlamydomonas reinhardtii. II. Flagellar membranes and the agglutination reaction.

A structural and biochemical study is presented concerning the agglutination of gametic flagella, the initial step in the mating reaction of Chlamydomonas reinhardtii. An alteration in the distribution of the intramembranous particles revealed by freeze-fracturing of flagella membranes is shown to accompany gametic differentiation in both mating types. The isolation and electrophoretic analysis of flagellar membranes and mastigonemes are reported; no electrophoretic differences can be detected when the membrane or mastigoneme glycoproteins from vegative and gametic cells are compared, nor when glycoproteins from the two mating types are compared, and no novel polypeptides are present in gametic preparations. The membrane vesicles, after they are freed of mastigonemes by sedimentation through a discontinuous sucrose gradient, are extremely active as an isoagglutinin, indicating a direct involvement of the membrane in the mating reaction.


Role of molecular charge in glomerular permeability. Tracer studies with cationized ferritins.

Mouse kidneys were perfused with Krebs-Ringer bicarbonate buffer (KRB) containing native, anionic horse spleen ferritin or various cationized derivatives, and the glomerular localization of the probe molecules determined by electron microscopy. Ferritins cationic with respect to the medium (KRB, pH 7.45) accumulated in the subendothelial layers of the glomerular basement membrane (GBM) in amounts far exceeding those observed with anionic ferritins, the degree being greater for the more cationized derivatives. Strongly cationized ferritins, in addition permeated the full thickness of the GBM in considerable amounts, but appeared to be retarded from entry into the urinary spaces at the level of the filtration slits. Very strongly cationized derivatives adhered to glomerular endothelium and GBM and formed aggregates in the outer layers of the latter. The results suggest that intrinsic negative charges are present in the GBM and endothelium, and that the barrier function of the glomerular capillary wall may be ascribed in part to its electrophysical properties.


Studies on the distribution of antigenic sites on the surface of rabbit spermatozoa.

Antibodies to rabbit spermatozoa isolated from immunized virgin female rabbits were conjugated to hemocyanin and have been used to determine the pattern of antigenic sites over the surface of rabbit spermatozoa under a variety of conditions. When the spermatozoa are incubated with antibody at 0 degrees C, labeling is almost entirely restricted to the postacrosomal sheath. Incubation at room temperature (22 degrees C) or at 37 degrees C results in progressively increased acrosomal labeling as well as enhanced postacrosomal sheath labeling. Initial incubation at low temperature followed by washing and high temperature incubation yields cells which indicate little tendency for postacrosomal sheath sites to migrate toward the acrosomal region. Absorption of the antibody preparation with rat lymphocytes has no effect on labeling density, whereas absorption with rabbit lymphocytes diminishes the intensity of labeling and yields cells with markers primarily over the postacrosomal sheath. It is concluded that the postacrosomal sheath plasma membrane has specific antigenic properties distinct from other regions of the head.


Biogenesis of microsomal membrane glycoproteins in rat liver. II. Purification of soluble glycoproteins and their incorporation into microsomal membranes.

Sialoproteins isolated from the soluble fraction of rat liver could be incorporated into microsomal membranes. This incorporation was dependent on protein concentration, time, and temperature. Sodium dodecyl sulfate gel electrophoresis of membrane proteins after in vitro incorporation showed four major sugar-containing peaks and was similar to that found after in vivo labeling. Most of the incorporated protein was tightly bound to the microsomal membrane. Gel filtration and ion-exchange chromatography revealed the presence of several cytosolic glycoproteins that could be incorporated into microsomes. During prolonged centrifugation in a KBr solution with a density of 1.21 a highly labeled ([3H]glucosamine) protein (mole wt approximately to 70,000) that was actively incorporated into microsomes could be recovered in the upper region of the tube. These results demonstrate that several cytoplasmic glycoproteins of rat liver are transferred into microsomal membranes and that one of these is a lipoprotein.


Biogenesis of microsomal membrane glycoproteins in rat liver. III. Release of glycoproteins from the Golgi fraction and their transfer to microsomal membranes.

The presence in the Golgi fraction of glycoproteins destined to be incorporated into the microsomal membrane was investigated. When incubated in sucrose, washed Golgi vesicles released four major, weakly acidic glycoproteins, some of which could be incorporated into microsomal membranes by incubation. Double labeling with [3H]glucosamine and [14C]leucine demonstrated the incorporation of both protein and oligosaccharide moieties, and the main peak of radioactivity was associated with the 70,000 mol wt region after SDS-gel electrophoresis. The proteins that could be incorporated into microsomes were probably associated to a large extent with the outer surface of the Golgi membrane. Centrifugation of the proteins released from the Golgi in a KBr solution (p = 1.24) resulted in a separation of glycoproteins, those in the top layer most actively incorporated into microsomes. The lipoglycoproteins in the top layer that could be incorporated appeared in the 70,000 mol wt region after SDS-gel electrophoresis, as did the corresponding proteins isolated from the supernate. These results suggest that glycoproteins with completed oligosaccharide chains are released from the Golgi system to the cytosol and are subsequently transferred to microsomes as constitutive membrane components.


Organization of an actin filament-membrane complex. Filament polarity and membrane attachment in the microvilli of intestinal epithelial cells.

The association of actin filaments with membranes is now recognized as an important parameter in the motility of nonmuscle cells. We have investigated the organization of one of the most extensive and highly ordered actin filament-membrane complexes in nature, the brush border of intestinal epithelial cells. Through the analysis of isolated, demembranated brush borders decorated with the myosin subfragment, S1, we have determined that all the microvillar actin filaments have the same polarity. The S1 arrowhead complexes point away from the site of attachment of actin filaments at the apical tip of the microvillar membrane. In addition to the end-on attachment of actin filaments at the tip of the microvillus, these filaments are also connected to the plasma membrane all along their lengths by periodic (33 nm) cross bridges. These bridges were best observed in isolated brush borders incubated in high concentrations of Mg++. Their visibility is attributed to the induction of actin paracrystals in the filament bundles of the microvilli. Finally, we present evidence for the presence of myosinlike filaments in the terminal web region of the brush border. A model for the functional organization of actin and myosin in the brush border is presented.


Initiation and growth of microtubules from mitotic centers in lysed mammalian cells.

Metaphase PtK1 cells, lysed into polymerization-competent microtubule protein, maintain a spindle which will gain or lose birefringence depending on the concentration of disassembled tubulin subunits used in the lysis medium. Concentrations of tubulin subunits greater than the equilibrium monomer value promote a rate and extent of birefringence increase that is proportional to the subunit concentration. Increase in spindle birefringence can be correlated with an increase in tubule number, though the relationship is not strictly linear. Increase in spindle tubule number is due to an vivo-like initiation of tubules at the mitotic centers, as well as tubulin addition onto pre-existing spindle fragments. Colcemid-treated prometaphase cells lysed into polymerization-competent tubulin develop large asters in the region of the centrioles and short tubules at kinetochores, making it unlikely that all microtubule formation in lysed cell preparations is dependent on tubulin addition to short tubule fragments. Asters can also form in colcemid-treated prometaphase cells lysed in tubulin that is incapable of spontaneous tubule initiation, suggesting that the centriolar region serves a tubule-initiator function in our lysed cell preparations. The ability of the centriole to initiate microtubule assembly is a time-dependent process-a ripening effect takes place between prophase and late prometaphase. Ripening is expressed by an increase in the number and length of tubules found associated with the centriolar region.


DNA replication in mammalian cells. Altered patterns of initiation during inhibition of protein synthesis.

The effects of inhibition of protein synthesis by the antibiotics cycloheximide and puromycin on the initiation of DNA replication in mouse L cells were studied. Cellular DNA was pulse labeled with [3H]thymidine of high, then of low specific activity and prepared for fiber autoradiography. Autoradiograms containing multiple (up to four) replication units were analyzed. In control cells, the proportion of replication units that initiated during a 10-min, high specific activity pulse was approximately equal to the proportion initiating immediately before the pulse. The addition of cycloheximide or puromycin at the start of the pulse inhibited the frequency of initiation in that there was a decrease by up to one-third of units initiating during the pulse relative to controls. Replication direction was also altered. Addition of the antibiotics 2 h before the pulse reduced the proportion of bidirectional units observed from 0.98 to 0.70. Antibiotic treatment for 2 h also decreased initiation synchrony in that the proportion of multiunit autoradiograms on which neighboring units showed similar replication patterns (indicating temporally coordinated initiation) was reduced by one-half. These observations indicate that inhibition of protein synthesis alters the normal pattern of DNA initiation.


Changes in cholinergic synaptic vesicle populations and the ultrastructure of the nerve terminal membranes of Narcine brasiliensis electron organ stimulated to fatigue in vivo.

Narcine brasiliensis electric organ was stimulated to fatigue in vivo. Electrical display of organ output and biochemical assay of bound acetylcholine (ACh) and ATP in isolated vesicles were used to assess the state of fatigue relative to denervated control organs of the same fish. A morphometric analysis of the fate of the synaptic vesicle populations in the nerve terminals was carried out. Statistically significant morphological changes in vesicle populations and plasma membranes were observed between control and fatigued electroplaque stacks from individual fish. Pooled data from several fish were used to evaluate the possible role of the different vesicle types in neurotransmission. Fatigue resulted in the loss of 49% of the total vesicle population and a 76% loss of vesicles with bound calcium (Ca). An approximately equivalent increase in the nerve-terminal plasma membrane area was measured. This was predominantly in the form of fingerlike protrusions and/or invaginations of the terminals which were present in the control organs but which were significantly increased by stimulation. Vesicle attachments to the nerve terminal membrane were reduced by 90%. This suggests that the failure in transmission may be due to reduction in the number of vesicles which are loaded with transmitter and can attach to the terminal membrane. The Ca-binding capacity of the lost vesicles was not transferred to the plasma membranes. This result was interpreted as support for the hypothesis that vesicle-bound ATP provides the Ca-binding site.


Segmental differentiations of cell junctions in the vascular endothelium. The microvasculature.

Small vascular units consisting of an arteriole, its capillaries, and the emerging venule (ACV units) were identified in the rat omentum and mesentery. They were fixed in situ and processed for electron microscopy either as whole units or as dissected segments. Systematic examination of the latter (in thin sections, as well as in freeze-cleaved preparations) showed that the intercellular junctions of the vascular endothelium vary characteristically from one segment to another in the microvasculature. In arterioles, the endothelium has continuous and elaborate tight junctions with interpolated large gap junctions. The capillary endothelium is provided with tight junctions formed by either branching or staggered strands; gap junctions are absent at this level. The pericytic venules exhibit loosely organized endothelial junctions with discontinuous low-profile ridges and grooves, usually devoid of particles. No gap junctions were found in these vessels. The endothelium of muscular venules has the same type of junctions (discontinuous ridges and grooves of low profile); in addition, it displays isolated gap junctions of smaller size and lower frequency than in arterioles. The term communicating junction (macula communicans) is proposed as a substitute for gap junctions, since the latter is inappropriate, in general, and confusing in the special case of the vascular endothelium.


Isolation of liver lysosomes by iron loading. Ultrastructural characterization.

In summary, the data demonstrate that, by the use of repeated injections of an iron sorbitol complex, it is possible to isolate a fraction highly enriched in hydrolytic enzymes (60 times over the homogenate) and in well preserved lysosomes emanating almost entirely from liver parenchymal cells. The advantage of adding fixative to the bottom of the gradient and of using en bloc staining with uranyl acetate is also demonstrated.


Distribution of binding sites for human chorionic gonadotropin in the preovulatory follicle of the rat.

The distribution of binding sites for human chorionic gonadotropin (hCG) in the preovulatory follicle was studied by autoradiography. An ovulatory dose (10 IU/rat) of [125I]hCG (1.4 muCi/IU) was administered intravenously, and large Graafian follicles were isolated 3 h later by microdissection. Injection of excess unlabeled hCG (500 IU/rat) prevented uptake of radioactivity by the follicle, indicating that binding of iodinated hormone was confined to specific and saturable receptor sites. The density of bound hormone molecules was highest in the theca interna and in three to four layers of mural granulosa cells adjacent to the basement membrane; labeling was chiefly associated with the cell borders. No significant binding could be detected either on the oocyte or on the cumulus cells surrounding the oocyte. We therefore suggest that the induction of ovum maturation does not require attachment of the hormone to the oocyte itself or to follicle cells in its immediate vicinity.


Calcium in smooth muscle sarcoplasmic reticulum in situ. Conventional and X-ray analytical electron microscopy.

Numerous electron-opaque deposits appear in the SR of the relaxed smooth muscle cells of the guinea pig Taenia coli that had been treated, before fixation, with a depolarizing medium containing oxalate to precipitate calcium ions in situ. X-ray spectra obtained by spot and line-scanning analyses of these deposits in situ show characteristic calcium signals, thus providing direct evidence for calcium accumulation inside the sarcoplasmic reticulum of smooth muscle.


Chemical modification of membrane proteins in relation to inhibition of anion exchange in human red blood cells.

Mono-, di-, and trisulfonic acids, including 4,4'-diacetamido stilbene-2,2'-disulfonic acid (DAS) and 2-(4'-amino phenyl)-6-methylbenzene thiazol-3',7-disulfonic acid (APMB) produce a reversible inhibition of sulfate equilibrium exchange in human red cells. A study of the sidedness of the action of a number of these sulfonic acids in red cell ghosts revealed that some, like DAS, inhibit only at the outer membrane surface while others, like APMB, inhibit at either surface. This finding suggests that at least two different types of membrane sites are involved in the control of anion permeability. The nature of the anion permeability controlling sites in the outer cell surface was investigated by studying the effects of DAS on the inhibition by dinitrofluorobenzene (DNFB) of anion equilibrium exchange and on the binding of DNFB to the proteins of the red blood cell membrane. After exposure to DNFB in the presence of DAS for a certain period of time, there was a reduction of both the inhibitory effect of DNFB on sulfate exchange and the binding of DNFB to the protein in band 3 of SDS polyacrylamide gel electropherograms (nomenclature of Steck, J. Cell. Biol., 62: 1, '74). Since binding to other membrane proteins was not affected, this observation supports the assumption that the protein in band 3 plays some role in anion transport. In accordance with the absence of an inhibitory effect at the inner membrane surface, internal DAS does not affect DNFB binding to the protein in band 3. DAS protected the anion exchange system not only against inhibition by DNFB but also by m-isothiocyanato benzene sulfonic acid. In contrast to DAS, the equally inhibitory phlorizin does not reduce the rate of dinitrophenylation of the protein in band 3. This suggests that either not all inhibitors of anion exchange exert their action by a combination with sites on the protein in band 3 or that in spite of the described evidence this protein is not involved in the control of anion movements.


Development of excitability in embryonic chick skeletal muscle cells.

During embryonic and early postnatal development, the chick leg muscle cells undergo a series of changes in their electrical responses in the following sequence: passive response, plateau response, plateau plus spike response and spike response. This suggests that the electrogenetic mechanism of muscles matures during development; a mechanism producing the plateau may first be induced, and then that producing the spike. The plateau is sensitive to manganese or cobalt ions, while the spike to tetrodotoxin. This suggests that the plateau is related to the increase in permeability to calcium ions, while the spike to sodium ions.


Polyamine metabolism in a rat brain tumor cell line: its relationship to the growth rate.

To investigate whether the metabolism of the polyamines putrescine, spermidine and spermine is related to cellular growth rate, we have measured the activities of L-ornithine decarboxylase and S-adenosyl-L-methionine decarboxylase as well as the levels of the polyamines in rat brain tumor cells at various stages of a 7-day in vitro growth period and correlated them with the continuous changes in specific growth rate ([dN[t]/dt]/N[t]). L-Ornithine decarboxylase and S-adenosyl-L-methionine decarboxylase both exhibited their maximal activities at the time of most rapid growth. A high positive correlation between the activities of these enzymes and the specific growth rate of the tumor cells during the entire growth period was demonstrated statistically. The pattern of fluctuation of the spermidine content during the culture cycle was similar to those of the enzyme activities and likewise showed a high positive correlation with the specific growth rate of the tumor cells during the entire growth period. The putrescine content exhibited a low positive correlation, whereas the spermine content exhibited a somewhat higher, but negative correlation with the specific growth rate. The high correlation between the specific growth rate of the tumor cells and the synthesis of the polyamines indicates that these events are primarily associated with processes involved in cell replication. Putrescine and spermidine are thought to participate in the regulation of cellular growth rate; a high content may augment, and a low content may restrain, cellular growth rate.


The effects of a glucocorticoid on the cell surface of RLC-GAI cells.

The purpose of these studies was to examine the effects of a synthetic glucocorticoid, dexamethasone sodium phosphate, on the cell surface of an epithelial cell line, RLC-GAI, and to investigate the mechanism of these effects. Within hours after addition of dexamethasone sodium phosphate to the cultures, the cells begin to spread going from a more bipolar to a more epithelioid form; this change is maximal by 24 hours. In the spread cells the density of surface microvilli, as visualized in the scanning electron microscope, is considerably reduced. The changes in cell surface and shape elicited by the glucocorticoid are blocked by actinomycin D but not by hydroxyurea. Cell spreading is probably related to the configuration of cell microfilaments since these are increased in numbers in the presence of the hormone and spreading is inhibited by cytochalasin B. An important role of microfilaments in the general mechanism of action of glucocorticoids is suggested.


A mechanical dissociation method for preparation of muscle cell cultures.

A cell preparation method by which large numbers of embryonic chick skeletal muscle cells may be obtained is described. The procedure requires fewer manipulations and much less time than standard trypsinization. By the criteria used, both methods are comparable with respect to percent viable cells and survival of plated cells. However, in addition to the ease of preparation, the mechanical dissociation method offers the significant advantage that the cell suspension is greatly enriched for myoblasts without the necessity of an additional preplating step.


Possible limitation of growth in human fibroblast cultures by diffusion.

Secondary cultures of human diploid fibroblasts which demonstrated density dependent inhibition of cell growth (DDI) were used to study the possible limitation of growth in cell cultures by diffusion. An oscillating platform system is described which insures constant mixing of the medium during the culturing period. Using this system, it was found that a greater number of cells in density inhibited cultures, grown to confluence for four days after initial seeding, could be stimulated to resume growth by a fresh medium change if the cultures were incubated on the oscillating platform than if the cultures were left undisturbed. This greater stimulation on the platform was probably not due to mechanical alterations on the surface of the cells due to motion of the medium as judged by TCA precipitable material released into the medium from cells prelabeled with glucosamine-3H. In spite of this greater stimulation after a single treatment with fresh medium, refeeding the cells on the platform every other day was a 12-day period did not affect the final saturation density achieved in the cultures. The results indicate that diffusion limitation of growth might occur under certain circumstances but that it cannot account entirely for the phenomenon of DDI.


Initiation of 3T3 fibroblast cell division by epidermal growth factor.

Epidermal Growth Factor (EGF) at concentrations of 10(-9) to 10(-10) M initiates cell division in both confluent and low density non-dividing 3T3 cells. Four days after addition of EGF to confluent or low density non-dividing 3T3 cells there is a 2- and 5-fold increase, respectively, in cell number.


Infrequent chromosome aberrations in Syrian hamster cells following partial synchrony by amino-acid deprivation.

Incubation of Syrian hamster embryo secondary cell cultures in isoleucine or arginine deficient medium inhibited cell multiplication; 4-7% of the cells were synthesizing DNA compared to approximately 40% for cells in complete medium. After the deficient medium was replaced with complete medium, cells resumed multiplication and within 12 hours 65--70% of the cells entered into the S phase. A second peak of labeled cells, approximately 55%, occurred 24 hours after addition of complete medium. Chromosomal damage characteristic for cell lines grown in amino acid deficient medium did not occur with these Syrian hamster cells. Isoleucine or arginine deprivation resulted in chromosomal or chromatid aberrations in only 2-5% of the cells, whereas chromosomes of control cells in complete medium occasionally exhibit chromatid gaps (less than 1% of the cells).


Selective depletion of chromosomes in a stable mouse-Chinese hamster hybrid cell line using antisera directed against species-specific cell surface antigens.

A chromosomally-stable mouse-Chinese hamster hybrid cell line was subjected to five rounds of selection with cytotoxic antisera raised in rabbits against either the parental mouse 3T3 cells or the parental Chinese hamster Wg-1 cells. Routine karyological analysis of clones isolated at each stage of serum selection revealed that treatment with either serum resulted in a limited loss of chromosomes (compared to the untreated hybrid cell cultured in parallel) and that the pattern of chromosome loss could not be correlated with the particular antiserum used for selection. However, more detailed analysis with the SSC-formamide C-banding technique, which identifies chromosomes containing a mouse centromere region, demonstrated that while large-scale chromosome loss was not achieved as a result of antiserum selection, the limited loss of chromosomes did, in fact, reflect a specific depletion of chromosomes in response to treatment with cytotoxic antiserum. Specific chromosomal elimination was shown to occur as early asthe first round of antiserum treatment. Antigenic analysis of the serum-selected clones revealed a quantitative decrease in the expression of the species-specific surface antigens selected against, but no qualitative loss of antigens was detected. The results suggest that treatment with cytotoxic antiserum may select for clones that have lost specific chromosomes bearing genes regulating the expression of species-specific surface antigens, rather than for those demonstrating large-scale depletion of chromosomes bearing the corresponding structural genes.


Modulation in the rates of incorporation of lipid precursors during the cell cycle.

The rates of incorporation of 3H-choline into phospholipid and of 3H-fucose into glycolipid have been measured during the cell cycle of the murine mastocytoma, P815Y, synchronized by either velocity sedimentation or excess thymidine blockade. The rate of 3H-choline incorporation into acid-insoluble material exhibited two distinct maxima coincident with the early S and G2 periods, whereas the rate of incorporation of 3H-fucose into lipid extractable material was maximal during the G2 period. Variation in rate of incorporation of 3H-choline could not be accounted for by changes in membrane permeability.


Interaction of steroids with the transport system of glucose in human erythrocytes.

Steroids inhibit the exchange transport of glucose in human erythrocytes. The extent of inhibition is roughly correlated to the affinity of the steroids to the membrane lipids. All C-21-steroids tested show a competitive inhibition while the C-19-steriods show different types of inhibition. 5Beta-androstane-3,17-dione acts as a competitive inhibitor. The inhibition by testosterone is of mixed type, while with androst-4-ene-3,17-dione and 5alpha-androstane-3,17-dione a non-competitive inhibition is observed. In this case two inhibitor molecules can be bound per transport molecule. The "non-competitive" inhibitors compete also to some extent with the glucose binding. This effect, however, is at high inhibitor concentrations masked by the more powerful non-competitive inhibition. Competitive and non-competitive inhibitors compete with each other. The structural requirements for the different types of inhibition are discussed.


Observations with cytochemistry and ultracryotomy on the fine structure of the expanding walls in actively elongating plant cells.

Ultracryotomy with negative staining and cytochemistry (periodic acid - thiocarbohydrazide - silver proteinate test for polysaccharides, in conjunction with mild extractions) were used to study the architecture of the cell wall and its modifications during expansion. Those techniques were applied to the study in situ of the walls of actively elongating parenchyma of mung bean (Phaseolus aureus), and pea (Pisum sativum) root and of collenchyma of celery (Apium graveolens) petioles. These complementary techniques provide information on the 3-dimensional disposition and fine structure of the subunits of the wall. In all the examples examined, the bulk of growing primary wall appears well-ordered and no progressive evolution from a transverse texture near the plasmalemma to a scattered texture near the middle lamella was observed. It seems unlikely that the development of the wall structure in relation to growth could be explained mechanically by a passive shift of the fibrillar elements in response to cellular stress. There is no evidence for an inert change in fibrillar orientation in the major part of the wall. If such occurs the process is limited to the outermost and senescent part of the wall. Thus, the texture observed does not agree with the classical multinet growth hypothesis but rather with the idea of an ordered structure of the primary wall. With the latter, the components should be able to respond in different ways to specific growth regulators and other environmental signals and thus exert a more positive control over the processes of oriented cell growth.


Supercoils in human DNA.

The three-dimensional structure of a double-stranded DNA molecule may be described by distinguishing the helical turns of the DNA duplex from any superhelical turns that might be superimposed upon the duplex turns. There are characteristic changes in the hydrodynamic properties of superhelical DNA molecules when they interact with intercalating agents. The hydrodynamic properties of nuclear structures released by gently lysing human cells are changed by intercalating agents in this characteristic manner. The characteristic changes are abolished by irradiating the cells with gamma-rays but may be restored by incubating the cells at 37 degrees C after irradiation. These results are interpreted as showing that human DNA is supercoiled. A model for the structure of the chromosome is suggested.