Influence of donor lymphocytes on the incidence of primary graft failure after allogeneic bone marrow transplantation in a murine model

We used a murine model to determine the impact of donor lymphocyte subsets on the incidence of primary marrow graft failure after transplantation of lymphocyte-depleted bone marrow. After lethal irradiation with 7.5 Gy, Balb/c mice received 1 x 10(5) to 4 x 10(7) GvH-nonreactive (C57 x Balb)F1 or GvH-reactive C57Bl/6 marrow cells. Pretreatment with anti-Thy-1.2, anti-CD4/CD8, anti-asialo-GM1 or L-leucyl-L-leucine methyl ester (Leu-Leu-OMe) was employed to eliminate T lymphocytes and/or natural killer cells. Primary graft failure was defined as death with neutrophils < 0.5 x 10(9)/l. To assess long-term chimaerism, the percentage of H-2b-positive spleen cells was determined. Pretreatment with anti-Thy-1.2, anti-CD4/CD8 or Leu-Leu-OMe successfully eliminated GvHR-induced mortality. Graft failure rates gradually declined from 88% after transplantation of 1 x 10(5) cells to 0% after transplantation of 4 x 10(7) C57Bl/6 cells. The incidence of graft failure, however, was not altered by T-cell depletion, provided that the unspecific loss of marrow cells was compensated for. After transplantation of GvH-nonreactive (C57 x Balb)F1 bone marrow, neither ex-vivo treatment with anti-Thy-1.2 and anti-asialo GM1 nor addition of 1 x 10(7) donor thymocytes to the allograft significantly influenced engraftment. The data obtained in our animal model suggest that the total number of marrow cells is of critical importance for successful marrow engraftment and not the presence or absence of T cells, NK cells or GvHR.

Epidural anesthesia for labor in an ambulatory patient

The effectiveness of two epidural analgesic regimens on the ability to ambulate was compared in women in labor by a prospective, randomized, double-blind design. One group of patients received epidural fentanyl, a 75-micrograms bolus and an infusion of fentanyl 2.5 micrograms/mL at 15 mL/h (FENT, n = 53). A second group received ultra low-dose bupivacaine (0.04%), epinephrine (1.7 micrograms/mL), and fentanyl (1.7 micrograms/mL) (BEF, n = 77), a 15-mL bolus followed by an infusion at 15 mL/h. Adequate analgesia was rapidly obtained in 90.6% of patients in the FENT group and 92.2% of patients in the BEF group (P = 0.89). Seventy percent of patients in the FENT group ambulated versus 68% in the other group. The BEF mixture provided analgesia of longer duration (287 +/- 171 min versus 156 +/- 72 min, P = 0.0001). The number of patients delivering during administration of only their study drug (without needing higher doses of local anesthetics) was 52% for BEF and 21% for FENT (P = 0.0005). Hip flexion weakness precluding ambulation occurred in 17% (P = 0.002) of BEF patients and orthostatic hypotension in 9% (P = 0.08). Neither problem occurred in FENT patients. Neonatal outcome was similar in both groups. Approximately 70% of women receiving epidural analgesia with fentanyl or ultra low-dose bupivacaine, epinephrine, and fentanyl may ambulate safely during labor.

Repeated complete remission in a patient with acute promyelocytic leukemia after treatment with 13-cis-retinoic acid first and with all-trans-retinoic acid in relapse

The use of retinoic acid is a new approach in the treatment of acute promyelocytic leukemia. We outline the therapy in a 61-year-old patient with acute promyelocytic leukemia who had not responded to standard chemotherapy but in whom the administration of 13-cis-retinoic acid resulted in complete remission for 24 months. In relapse the patient was treated with all-trans-retinoic acid in combination with two cycles of daunorubicin and cytosine arabinoside and achieved another complete remission.

Far fewer missed opportunities for immunisation in an integrated child health service

The mobile nature of the population of Khayelitsha makes it imperative that opportunities for immunisation of children are exploited at every visit to health services. Previous studies have demonstrated a high incidence of missed opportunities for immunisation at curative health services. The occurrence of undetected opportunities for immunisation are compared at two primary care institutions: one in which curative and preventive services are provided separately, and one in which these functions are integrated. Far fewer opportunities for immunisation were missed at the integrated service, underscoring the urgency of integrating child health services throughout the country.

High-dose chemotherapy and hematopoietic stem cell rescue in patients with relapsed Hodgkin's disease

Fifty-one consecutive patients with Hodgkin's disease (HD) have been treated with high-dose chemotherapy (HDT) and transplantation of autologous bone marrow (BM) (n = 44), autologous BM plus peripheral blood stem cells (PBSC) (n = 2), PBSC (n = 1), syngeneic (n = 1), or allogeneic BM (n = 3). All patients had received standard salvage chemotherapy prior to HDT and were classified as sensitive (n = 33) or resistant (n = 17) to this treatment; one patient was in untreated relapse prior to BMT. The preparative regimens for patients receiving autologous BM and/or PBSC consisted of cyclophosphamide, VP 16, and BCNU (CVB) (n = 44) or BCNU, etoposide, ara-C, and melphalan (BEAM) (n = 3). The patients receiving allogeneic transplants were treated with the CVB regimen (n = 2) or busulfan (16 mg/kg body wt.) and cyclophosphamide (200 mg/kg body wt.). With a median follow-up of 12 months, overall survival for 44 patients grafted with autologous BM is 61% +/- 9%, progression-free survival for patients with sensitive disease is 44% +/- 11%; no patient with resistant relapse survived beyond 1 year post transplant. Two of three patients grafted with allogeneic BM still survive 15 and 24 months after BMT with Karnofsky performance scores of 70% and 100%, respectively. The main toxicity encountered with the CVB regimen was interstitial pneumonia (IP), seen in four of 15 patients (27%) receiving > or = 600 mg/m2 of BCNU. Three of these patients have died. The results show that HDT followed by hematopoietic stem cell rescue may effectively salvage an important fraction of patients with relapsed HD who respond to standard chemotherapy. The same approach is largely unsuccessful in patients with proven refractoriness to standard chemotherapy. Whether HDT followed by BMT or PBSC support is superior to intensive chemotherapy without stem cell support can be answered only by a prospectively randomized trial.

Graft-versus-leukemia activity after bone marrow transplantation does not require graft-versus-host disease

Clinical data have suggested that graft-versus-host disease (GVHD) plays a crucial role in the antileukemic effects of bone marrow grafts. We investigated (a) whether bone marrow cells unable to induce GVHD can effect graft-versus-leukemia (GVL) activity and (b) whether such antileukemic capacity depends on the presence of T lymphocytes in the graft. Balb/c mice were inoculated with A20 cells, a B-cell lymphoma/leukemia of Balb/c origin. Four weeks after tumor inoculation the animals were lethally irradiated and received a bone marrow graft. Cells from (Balb/c x C57) F1 or (C3H x Balb/c) F1 hybrids were transplanted into parental-strain Balb/c mice. Since lymphocytes from F1 hybrids are unable to cause graft-versus-host reactivity against a parental-strain animal, we used this experimental setting to explore GVL effects in a GVHD-free system. In vitro incubation with monoclonal anti-Thy-1.2 antibody plus complement was used to eliminate Thy-1+ cells. After syngeneic transplantation, the death rate due to leukemia remained unchanged (91%) compared with that among untreated animals (86%). Following transplantation of F1 marrow cells of either (C57 x Balb/c) F1 or (C3H x Balb/c) F1 origin, death rates of 40% and 50% were observed; these were significantly lower. Depletion of Thy 1+ cells from bone marrow graft caused only a slight increase in the leukemic death rate after transplantation of bone marrow of (C57 x Balb/c) F1 hybrid origin (50%), but a high leukemic death rate was seen after transplantation of (C3H x Balb/c) F1 bone marrow (100%). Additional experiments with fully allogeneic, T-cell-depleted C57 bone marrow transplantation suggest an antileukemic effect that is comparable to that seen after transplantation of unmanipulated F1 bone marrow. Taken together, our results indicate that GVL activity can be dissociated from graft-versus-host reaction.

Influence of cell dose and graft-versus-host reactivity on rejection rates after allogeneic bone marrow transplantation

The number of cells transplanted and their capacity to induce graft-versus-host reactivity (GvHR) are two factors that are suspected to influence the engraftment of allogeneic bone marrow. We have investigated their impact on graft rejection rates in busulfan-treated LEW rats. In a series of experiments, we varied (1) the number of marrow cells transferred (1, 5, 10, 20, 30, and 40 x 10(7)), (2) the degree of pretransplant immunosuppression (1.5, 3.0, and 4.5 Gy of total body irradiation [TBI]; 0, 30, 60, 90, 120, and 180 mg/kg cyclophosphamide), and (3) the ability of the marrow graft to induce classical GvHR against major histocompatibility complex (MHC) antigens [semiallogeneic (CAP x LEW)F1 or CAP rats as marrow donors]. Reducing either the immunosuppressive pretreatment or the number of cells transplanted resulted in a stepwise increase in rejection rates. However, every reduction in the size of the marrow inoculum was compensated by increased immunosuppression and vice versa. While 60 mg/kg cyclophosphamide was sufficient to prevent rejections after grafting of 40 x 10(7) cells, 90 mg/kg was necessary to ensure 100% engraftment after transplantation of 20 x 10(7) cells, 120 mg/kg after 10 x 10(7) cells, and 180 mg/kg after 1 x 10(7) cells. Since CAP marrow leads to GvHR-mediated immunosuppression in LEW recipients, in contrast to (CAP x LEW)F1 marrow, we had supposed that lower cell numbers or cyclophosphamide doses are sufficient to achieve engraftment of CAP marrow. Although severe GvHR was present in all animals receiving escalating doses of CAP cells, the rejection rates were the same as for (CAP x LEW)F1 marrow. In conclusion, we have demonstrated that there is a sensitive balance between the immunosuppression of the host and the number of marrow cells transferred. We were not able to number of marrow cells transferred. We were not able to detect a beneficial effect of classical GvHR against MHC antigens on the engraftment of allogeneic marrow. Thus, our results do not support the hypothesis that the loss of GvHR-mediated immunosuppression is responsible for higher rejection rates following transplantation of T-cell-depleted bone marrow.

High-dose cytostatic agents in allogeneic bone marrow transplantation: comparison of the engraftment promoting potential

We investigated the potential of various cytostatic agents for preventing graft rejection following allogeneic bone marrow transplantation. LEW rats received a lethal dose (35 mg/kg) of busulfan followed by injection of 1 x 10(8) F1(CAP x LEW) marrow cells, which are unable to induce a graft-versus-host reaction in LEW recipients. Rejection of the marrow graft was assessed by monitoring haematocrit and granulocyte counts. Due to its weak immunosuppressive activity, busulfan by itself is unable to allow engraftment of allogeneic marrow. Therefore, agents administered in addition to busulfan can be tested for their capacity to prevent marrow graft rejection. 120 mg/kg of cyclophosphamide, 20 mg/kg of ACNU and 240 mg/kg of ifosfamide completely prevented rejection of the allogeneic marrow. Maximum doses of BCNU applicable in conjunction with busulfan reduced the rejection rate to 12% (30 mg/kg) and 17% (40 mg/kg), whereas the antitumour agents thiotepa, melphalan, and carboplatin exhibited a very limited engraftment-promoting potential in this experimental setting. Thus, BCNU (carmustine), ACNU (nimustine), and ifosfamide might be suitable candidates for conditioning of allogeneic bone marrow graft recipients.

Ifosfamide and ACNU in experimental allogeneic bone marrow transplantation

We have tested ifosfamide and ACNU for their effectiveness in preventing graft rejection following allogeneic bone marrow transplantation. The engraftment-promoting potency of both was compared to that of the standard agent cyclophosphamide. LEW rats received a lethal dose (35 mg/kg) of busulfan followed by injection of 1 x 10(8) (CAP x LEW) F1 marrow cells, which are unable to induce a graft vs host reaction in LEW recipients. Rejection of the marrow graft was assessed by monitoring haematocrit and granulocyte count either until death of the animal or until day 80. Surviving animals received a donor-type skin graft to confirm the persistence of allogeneic haematopoiesis. Because of its weak immunosuppressive properties, busulfan by itself is unable to allow engraftment of allogeneic marrow. Therefore, ifosfamide and ACNU and cyclophosphamide as the standard agent could be tested for their capacity to prevent marrow graft rejection. The following rejection rates were observed: cyclophosphamide: 30 mg/kg 100%, 60 mg/kg 60%, 90 mg/kg 20%, 120 mg/kg and 180 mg/kg 0%; ACNU: 3, 5, 7, and 10 mg/kg 100%, 15 mg/kg 45%, 20 and 30 mg/kg 0%; ifosfamide: 60-120 mg/kg 100%, 180 mg/kg 68%, 240 and 360 mg/kg 0%. Thus, 240 mg/kg ifosfamide or 20 mg/kg ACNU is nearly equivalent to the standard dose of 120 mg/kg cyclophosphamide in engraftment-promoting potency in allogeneic bone marrow transplantation.

Failure of prediction of liver function test abnormalities with the urine urobilinogen and urine bilirubin assays

A prospective observational study of 229 cases was conducted in a busy ambulatory care setting to evaluate the sensitivity, specificity, predictive values, and accuracy of spot urine urobilinogen and urine bilirubin assays as screening tests for serum liver function test (LFT) abnormalities. Both urine tests exhibited remarkably similar characteristics overall once they were adjusted to maximize accuracy and predictive values (occurring at a normal or abnormal "threshold," respectively, of 3.4 or 5.07 mumol/d for urobilinogen and 0 or 1+ for urine bilirubin). The percentage of cases correctly identified were 81% to 83% for serum bilirubin assays, 68% to 72% for other LFTs, but only 62% to 63% for screens for cases with at least one abnormal LFT finding. Poor sensitivities (47% to 49%) limited the detection of abnormal findings by the screen; both screens were reasonably specific (79% to 89%), but negative predictive values were suitable (89%) for serum bilirubin results only and were prohibitively lower (49% to 50%) in predicting all patients without LFT abnormalities. We conclude that spot urine urobilinogen and urine bilirubin determinations, although good screens for isolated serum bilirubin elevations, have unacceptable statistical properties as predictors of other LFT results due to a high proportion of false-negative results.

Abnormalities of urine urobilinogen and urine bilirubin assays and their relation to abnormal results of serum liver function tests

A prospective observational study of 324 cases was conducted in a busy ambulatory care setting to evaluate the sensitivity, specificity, predictive values, and accuracy of spot urine urobilinogen and urine bilirubin assays as screening tests for serum liver function test (LFT) abnormalities. High positive predictive values (88% for at least one abnormal LFT) make the evaluation of positive urine screens detected during routine health care maintenance examinations imperative. Because extraneous factors may influence both urine and serum test results, however, urine assays obtained as a screening parameter in clinical presentations (abdominal pain, jaundice, constitutional symptoms, etc) have only limited clinical utility. The high proportion of false-negative results for both urine assays renders their statistical properties unacceptable as screens in these clinical situations.

Development, implementation, and evaluation of a medical Spanish curriculum for an emergency medicine residency program

A 45-hour medical Spanish curriculum for an emergency medicine residency program was implemented in response to a need for "functionally bilingual" physicians in our practice setting, and to reduce reliance on translation assistance from nursing and clerical personnel. Course goals were to achieve a vocabulary level of 5,000-10,000 words for participants, and to achieve sufficient language capabilities for basic information exchange, obtaining uncomplicated medical histories, conducting unassisted physical examinations, and giving patient discharge instructions. Feedback obtained from post course interviews and instructor assessment indicated that the curriculum employed resulted in the attainment of the above goals for fully participating physicians.

Some aspects of virus shedding by rainbow trout (Salmo gairdneri Rich.) after waterborne infection with viral haemorrhagic septicaemia (VHS) virus

VHS virus shedding after experimental waterborne infection of rainbow trout was quantified by measuring virus infectivity in blood, faeces, and urine of catheterised fish. Virus shedding by urine with relatively high yields of infectious virus could be demonstrated during acute VHS until death, but not by faeces. Trout, which were vaccinated against VHS or had survived the disease but showed no detectable humoral antibodies, may excrete infectious virus via urine for more than 30 days and without any signs of VHS after a secondary challenge infection. These results reveal the development of a carrier status of rainbow trout after VHS exposure.

Milestones and rates of growth in the development of biology

An attempt has been made to examine the exponetial rate of increase of the great discoveries, the "milestones," in the rise of biology from the beginning of the seventeenth century, and particularly in the rise of genetics from the beginning of the twentieth century. The biological sciences in general, during the three centuries named, exhibit a doubling of the number of great discoveries in each fifty years. Genetics, in the twentieth century, has risen much faster. Its doubling time for the most significant discoveries has been about twenty-two and a half years. Either of these rates is of course far slower than the exponential rise in the total output of biological science, the number of scientists, or the cost of science, which have been generally reported to double about every ten years or less. It follows that, as time passes, and until these exponetial rates become considerably altered, a relationship of diminishing returns is quite evident. As time passes, even though the most significant discoveries continue to increase exponetially, it takes a greater total output, a greater number of (assisting?) scientists, and greater amounts of money to yield a set quantity of major new findings. The rapid rise of the life sciences cannot continue its present course into the twenty-first century without meeting ineluctable limits to expansion. It may be argued that as in other human spheres of activity, so too in natural science there are limits to growth which we are rapidly approaching. From the predictable asymptote only unpredictable breakthroughs might deliver us.

Paleomagnetic Study of Antarctic Deep-Sea Cores

The magnetic inclinations and inten sities of about 650 samples from seven deepsea cores taken in the Antarctic were measured on a spinner magnetometer. This series of measurements provided a magnetic stratigraphy, based on zones of normally or reversally polar ized specimens for each core, which was then correlated with the magnetic stra tigraphy of Cox et al. (1). One core (V16-134) gave a continuous record of the paleomagnetic field back to about 3.5 million years. When selected samples were subject ed to alternatingfield demagnetization, most were found to have an unstable component that was removed by fields of 150 oersteds; all samples from two cores were partially demagnetized in a field of 150 oersteds. The average inclination in these two cores was then in good agreement with the average inclination of the ambient field for the latitude of the core site. It was also found that the intensities of the samples decreased at the points of reversal; this finding is to be expected if, as has been postulated by the dynamo theory, the intensity of the dipole field decreases to zero and builds again with opposite polarity. We believe that the magnetiza tion of the cores results from the pres ence of detrital magnetite, although other magnetic minerals also may be present. Four faunal zones (, X, , and ) have been recognized in these Antarctic cores on the basis of upward sequential disappearance of Radiolaria. The faunal boundaries and reversals consistently have the same relations to one another, indicating that they are both timedependent phenomena. Using previously determined times of reversal, one may date the following events in the cores: 1) Radiolarian faunal boundaries:-X, 2 million years; X-, 0.7 million years; -, 0.4 to 0.5 million years. These dates are in good agreement with ages previously extrapolated from radio metric dates. 2) Initiation of Antarctic diatom ooze deposition, approximately 2.0 mil-lion years ago. 3) First occurrence of ice- rafted detritus, approximately 2.5 million years ago. One can also calculate rates of sedi mentation, which vary in the cores studied from 1.1 to about 8.0 millimeters per 1000 years. Sedimentation rates for the Indian Ocean cores are higher than for the Bellingshausen Sea cores. The near coincidence of faunal changes and reversals in the cores suggests but does not prove a causal relation. We conclude from this study that paleomagnetic stratigraphy is a unique method for correlating and dating deep sea cores, and that future work with such cores may provide a complete or nearly complete record of the history of the earth's magnetic field beyond 4 million years.

The Japanese science education centers

These six Japanese science education centers signify a sweeping reform of elementary and secondary school science teaching. They achieve their striking results because they are established on a permanent, local basis and are supported mainly by the local boards of education. They have avoided control by pedagogues and specialists in "education." Instead, they are operated by trained scientists and experienced school teachers who work together to devise programs specially suited to the needs of their teachers. With small and practicable steps, the teachers improve their understanding of methods which they can readily test in their own classrooms rooms and laboratories. The laboratory equipment in the science education centers is only slightly superior to that which the teachers have in their own schools, but superior enough to make them desire to improve their own facilities. Major facilities, such as x-ray machines, electron microscopes, telescopes (15-cm), and machine shops, as well as good working collections of minerals and fossils, and adequate greenhouses, permit the teachers to work with more expensive equipment, to gain a firsthand knowledge of its operation, and to bring groups of students to the center to observe what such instruments make possible. The use of American experimental course content improvement programs is widespread. Every science education center I visited is using PSSC, CHEMS, CBA, BSCS, or ESCP materials and studying the philosophy of these programs. Yet no center is entirely dependent on these programs, but uses them critically to supplement and improve its own courses. The emphasis is on good laboratory and field teaching as a basis for understanding scientific methods and concepts. Science as investigation and inquiry, instead of treatment solely as an authoritative body of facts, is coming into its own. The few defects of the science education centers of Japan inhere in the educational situation itself. The centers are at present inadequate to reach even a reasonable proportion of the science teachers within a 5-year, or even a 10-year cycle. The shortage of substitute teachers causes most of the courses to be far too brief for maximum effectiveness. Staff programming tends to be rather spotty instead of comprehensive. A major difficulty, frequently expressed, lies in the grim hold of the university entrance examination system over the science curricula of the lower schools. The university is the goal of every able student, for economic as well as intellectual reasons. To enter a university he must pass the examinations, which are established separately by each institution. The professor who makes out the examination questions therefore controls what must be taught and learned in the lower schools. This same rigorous control is in part reflected in the Ministry of Education syllabi, which must be followed by the teachers. Nevertheless, I found the men in the biological section of the Ministry of Education very enlightened and pressing for change. Many professors in the universities are also in the full current of modern biological thought, participate gladly in the programs of the science education centers, and would write examinations that emphasize interpreting data, applying tests to hypotheses, and drawing valid conclusions instead of merely memorizing and regurgitating facts. On the other hand, in many universities the upper positions are still filled by men to whom biology means classification rather than experimentation, morphology rather than biochemistry, organ physiology rather than cell biology. We cannot afford to discard taxonomy, morphology, or gross physiology-they are important parts of biology and will remain so. But they do not comprise all of biology-they are only a diminishing proportion of it. In Japan, as in the United States, the examination system must become more flexible. It must change with the development of science itself, must encourage scientific attitudes and cease defeating the introduction of new disciplines, new outlooks, new subject matter. The university and the examining boards in some educational systems indeed exhibit a rigor mortis. On balance, the science education centers in Japan may well represent the most significant educational experiment of our time. Their vitality, which springs from their local relationship to the prefectural schools and their permenent staffs, far exceeds in my own estimation that of most of the summer science institutes held in the United States, which lack that close relation to the local schools and which by their impermanency countenance ill-planned and ill-taught programs that are often little different from the usual summer school sessions. The best summer institutes in the United States are indeed very good, but far too few of them reach a passable standard. That is because, for the most part, their staffs are recruited quickly, teach their favorite subjects without much consideration of their appropriateness or suitability for improving science education in the lower schools, and depart without much contact with other members of the staff. What is needed is serious, continuous, prolonged, hard work devoted to the development of the right sorts of courses for renewing the training of science teachers. The Japanese seem to be achieving just that. We would do well, with our vast resources for the improvement of education, to emulate them. As they have profited by employing and improving upon our NSF supported programs in science education, we may likewise profit through the establishment of science education centers modeled on theirs.