Increased Arctic cloud longwave emissivity associated with pollution from mid-latitudes

There is consensus among climate models that Arctic climate is particularly sensitive to anthropogenic greenhouse gases and that, over the next century, Arctic surface temperatures are projected to rise at a rate about twice the global mean. The response of Arctic surface temperatures to greenhouse gas thermal emission is modified by Northern Hemisphere synoptic meteorology and local radiative processes. Aerosols may play a contributing factor through changes to cloud radiative properties. Here we evaluate a previously suggested contribution of anthropogenic aerosols to cloud emission and surface temperatures in the Arctic. Using four years of ground-based aerosol and radiation measurements obtained near Barrow, Alaska, we show that, where thin water clouds and pollution are coincident, there is an increase in cloud longwave emissivity resulting from elevated haze levels. This results in an estimated surface warming under cloudy skies of between 3.3 and 5.2 W m(-2) or 1 and 1.6 degrees C. Arctic climate is closely tied to cloud longwave emission, but feedback mechanisms in the system are complex and the actual climate response to the described sensitivity remains to be evaluated.

Evidence That Nitric Acid Increases Relative Humidity in Low-Temperature Cirrus Clouds

In situ measurements of the relative humidity with respect to ice (RHi) and of nitric acid (HNO3) were made in both natural and contrail cirrus clouds in the upper troposphere. At temperatures lower than 202 kelvin, RHi values show a sharp increase to average values of over 130% in both cloud types. These enhanced RHi values are attributed to the presence of a new class of HNO3-containing ice particles (Delta-ice). We propose that surface HNO3 molecules prevent the ice/vapor system from reaching equilibrium by a mechanism similar to that of freezing point depression by antifreeze proteins. Delta-ice represents a new link between global climate and natural and anthropogenic nitrogen oxide emissions. Including Delta-ice in climate models will alter simulated cirrus properties and the distribution of upper tropospheric water vapor.

Gemcitabine for relapsed or resistant lymphoma

BACKGROUND

Gemcitabine therapy has not been widely assessed in the treatment of hematological malignancies. We have examined the efficacy and safety of gemcitabine in patients with relapsed or resistant lymphoma.

PATIENTS AND METHODS

Gemcitabine (1 g/m2) was given weekly for 7 consecutive weeks, followed by a week off treatment. The drug was then given for 3 consecutive weeks, followed by a week off treatment; this regimen was continued until disease progression or drug intolerance. Fifteen patients have enrolled. Most have been extensively pre-treated for advanced diffuse large-cell or mantle-cell lymphoma.

RESULTS

The drug was well tolerated; no patient suffered treatment-related sepsis, hemorrhage or death. Non-hematopoietic toxicity led to discontinuation of gemcitabine therapy in two patients. Dose reductions or delays were required for about two-thirds of treatments. Of 13 evaluable patients, one had a complete response, 3 a partial response, 3 stable disease, and 6 disease progression. After 6 infusions of gemcitabine, a patient with advanced Hodgkin's disease has had a complete remission lasting 21 months.

CONCLUSIONS

Gemcitabine has substantial activity and acceptable toxicity in heavily pre-treated patients with advanced lymphoma. Further study is warranted.

High-dose thiotepa and etoposide-based regimens with autologous hematopoietic support for high-risk or recurrent CNS tumors in children and adults

The prognosis in patients with primary brain tumors treated with surgery, radiotherapy and conventional chemotherapy remains poor. To improve outcome, combination high-dose chemotherapy (HDC) has been explored in children, but rarely in adults. This study was performed to determine the tolerability of three-drug combination high-dose thiotepa (T) and etoposide (E)-based regimens in pediatric and adult patients with high-risk or recurrent primary brain tumors. Thirty-one patients (13 children and 18 adults) with brain tumors were treated with high-dose chemotherapy: 19 with BCNU (B) and TE (BTE regimen), and 12 with carboplatin (C) and TE (CTE regimen). Patients received growth factors and hematopoietic support with marrow (n = 15), peripheral blood progenitor cells (PBPC) (n = 11) or both (n = 5). The 100 day toxic mortality rate was 3% (1/31). Grade III/IV toxicities included mucositis (58%), hepatitis (39%) and diarrhea (42%). Five patients had seizures and two had transient encephalopathy (23%). All patients had neutropenic fever and all pediatric patients required hyperalimentation. Median time to engraftment with absolute neutrophil count (ANC) >0.5 x 10(9)/l was 11 days (range 8-37 days). Time to ANC engraftment was significantly longer (P = 0.0001) in patients receiving marrow (median 14 days, range 10-37) than for PBPC (median 9.5 days, range 8-10). Platelet engraftment >50 x 10(9)/l was 24 days (range 14-53 days) in children. In adults, platelet engraftment >20 x 10(9)/l was 12 days (range 9-65 days). In 11 patients supported with PBPC, there was a significant inverse correlation between CD34+ dose and days to ANC (rho = -0.87, P = 0.009) and platelet engraftment (rho = -0.85, P = 0.005), with CD34+ dose predicting time to engraftment following HDC. Overall, 30% of evaluable patients (7/24) had a complete response (CR) (n = 3) or partial response (PR) (n = 4). Median time to tumor progression (TTP) was 7 months, with an overall median survival of 12 months. These TE-based BCNU or carboplatin three-drug combination HDC regimens are safe and tolerable with promising response rates in both children and older adults.

The morphologic and molecular genetic categories of posttransplantation lymphoproliferative disorders are clinically relevant

BACKGROUND

Posttransplantation lymphoproliferative disorders (PT-LPDs) are a well-known complication of immunosuppression associated with solid organ transplantation. The clinical course of PT-LPDs is unpredictable; some patients experience regression of all lesions with a reduction in immunosuppression, whereas other patients, despite chemotherapy, radiation therapy, or surgery, rapidly die of their disease. In this study, the authors attempted to establish whether the previously described morphologic and molecular genetic categories of PT-LPD--plasmacytic hyperplasia (PH), polymorphic PT-LPD (polymorphic), and malignant lymphoma/multiple myeloma (ML/MM)--are clinically relevant and helpful in predicting the clinical outcome of patients who develop these lesions.

METHODS

To determine the clinical significance of the morphologic and molecular genetic categories of PT-LPDs, the clinical characteristics of 32 solid organ transplant recipients (26 heart, 5 kidney, and 1 lung), including age, time from transplantation to development of PT-LPD, stage of disease, and clinical outcome, were compared with the morphologic and molecular genetic features of the 41 PT-LPDs that they developed (15 PH in 12 patients, 19 polymorphic in 16 patients, and 7 ML/MM in 6 patients). Clinical outcome was defined by the following categories: 1) regression (after a reduction in immunosuppression) and surgical resolution (by surgical excision, with or without a reduction in immunosuppression); 2) medical resolution (by chemotherapy and/or radiation therapy); and 3) no response.

RESULTS

Although there was no difference in the time from transplantation to PT-LPD development among patients belonging to the three morphologic and molecular genetic categories, there was a significant difference in patient age at the time of PT-LPD development (P < 0.0098). Younger patients developed PH (mean age of 19 years), whereas older patients developed polymorphic PT-LPD (mean age of 35 years) and ML/MM (mean age of 56 years). Patients with PH presented with lower stages of disease (Stages I-II) than patients with ML/MM (P < 0.0004). Furthermore, there was a statistically significant trend between morphologic and molecular genetic category and clinical outcome, with decreased likelihood that lesions categorized as PH, polymorphic, or ML/MM would regress with a reduction in immunosuppression or be resolved by surgery, whereas those classified as ML/MM were more likely to exhibit no response to aggressive clinical intervention (P < 0.00006). Furthermore, no patients with PH died, whereas 20% with polymorphic PT-LPD and 67% with ML/MM died as a direct result of their PT-LPDs.

CONCLUSIONS

This study strongly suggests that classification of PT-LPDs into the morphologic and molecular genetic categories PH, polymorphic, PT-LPD and ML/MM is clinically relevant.

Systemic adjuvant therapy of breast cancer

Systematic adjuvant therapy has improved the outcome for women with operable breast cancer. As a result, a substantial proportion of patients with this disease are candidates for adjuvant treatment. In providing a woman with recommendations for therapy, her risk of developing recurrent breast cancer needs to be assessed in relationship to the degree of benefit she will obtain from treatment. With the range of presently available treatments, an individualized approach is necessary to provide the patient with options appropriate for her own situation. For women with a high risk of recurrence despite current standard adjuvant therapies, innovative approaches with high dose chemotherapy followed by infusion of autologous hematopoietic stem cells and growth factors are being evaluated. Ongoing clinical trials will demonstrate whether or not these newer therapies result in a better outcome.

Crystallization and preliminary X-ray analysis of (1,3)- and (1,3;1,4)-beta-D-glucanases from germinating barley

(1,3)-beta-D-Glucanase isoenzyme GII and (1,3;1,4)-beta-D-glucanase isoenzyme EII from barley have been crystallized by the hanging drop method in the presence of ammonium sulphate. The crystals of the (1,3)-beta-D-glucanase, which diffract to about 1.8 A resolution, belong to the trigonal space group P3(1)2(1)2 (or P3(2)2(1)2) with cell constants a = b = 86.9 A, c = 156.0 A and contain two molecules in the asymmetric unit. The crystals of the (1,3;1,4)-beta-D-glucanase which diffract to better than 1.8 A resolution, belong to the tetragonal space group P4(3)2(1)2 (or P4(1)2(1)2) with cell constants a = b = 87.4 A, c = 109.5 A and contain one molecule in the asymmetric unit.

Posttransplantation lymphoproliferative disorders treated with cyclophosphamide-doxorubicin-vincristine-prednisone chemotherapy

BACKGROUND

Posttransplantation lymphoproliferative disorders after solid organ transplantation are a serious complication occurring in 1-10% of patients. Different therapies have been used, but the optimal treatment is unknown. There is relatively little information in the literature on the experience with cytotoxic chemotherapy.

METHODS

The disease stage of patients with biopsy-documented posttransplantation lymphoproliferative was determined with standard methods to establish the extent of the disease. Patients in whom the disease failed to regress after initial management, which included reduction in immunosuppression, were treated with a combination chemotherapy regimen consisting of six cycles of cyclophosphamide, doxorubicin, vincristine, and prednisone (CHOP). Response to therapy was determined by following previously defined sites of disease with appropriate tests. Patients were maintained on a reduced dose of immunosuppressants.

RESULTS

In the four patients studied, lymphoproliferative disorders developed after heart (three cases) or lung (one case) transplantation, which did not regress after immunosuppression was reduced. All four experienced a complete remission with CHOP chemotherapy, which continued at 3, 13+, 20 and 30+ months after completion of treatment. One patient died of sepsis after completing therapy at a point when his leukocyte count was normal, and no evidence of posttransplantation lymphoproliferative disorder was found at autopsy. A second patient died of liver failure with no clinical evidence of lymphoproliferative disorder.

CONCLUSION

Although this is a small series, it demonstrates that patients with posttransplantation lymphoproliferative disorders may respond to cytotoxic chemotherapy. The duration of response is undetermined.

Vertebral artery thrombosis due to motor vehicle accident

Vertebral artery injury is a relatively rare cause of neurologic deficits occurring after blunt trauma. We present the case of a man involved in a motor vehicle accident with resulting vertebral artery injury whose symptoms did not appear until several hours after his initial evaluation in the emergency department. The mechanisms, pathogenesis, presentation, and treatment of these injuries are discussed.

Neurologic aspects of cobalamin deficiency

We reviewed 153 episodes of cobalamin deficiency involving the nervous system that occurred in 143 patients seen over a recent 17-year period at 2 New York City hospitals. Pernicious anemia was the most common underlying cause of the deficiency. Neurologic complaints, most commonly paresthesias or ataxia, were the first symptoms of Cbl deficiency in most episodes. The median duration of symptoms before diagnosis and treatment with vitamin B12 was 4 months, although long delays in diagnosis occurred in some patients. Diminished vibratory sensation and proprioception in the lower extremities were the most common objective findings. A wide variety of neurologic symptoms and signs were encountered, however, including ataxia, loss of cutaneous sensation, muscle weakness, diminished or hyperactive reflexes, spasticity, urinary or fecal incontinence, orthostatic hypotension, loss of vision, dementia, psychoses, and disturbances of mood. Multiple neurologic syndromes were often seen in a single patient. In 42 (27.4%) of the 153 episodes, the hematocrit was normal, and in 31 (23.0%), the mean corpuscular volume was normal. Neutropenia and thrombocytopenia were unusual even in anemic patients. In nonanemic patients in whom diagnosis was delayed, neurologic progression frequently occurred although the hematocrit remained normal. In 27 episodes, the serum cobalamin concentration was only moderately decreased (in the range of 100-200 pg/ml) and in 2 the serum level was normal. Neurologic impairment, as assessed by a quantitative severity score, was judged to be mild in 99 episodes, moderate in 39 and severe in 15. Severity of neurologic dysfunction before treatment was clearly related to the duration of symptoms prior to diagnosis. In addition, the hematocrit correlated significantly with severity, independent of the longer duration of symptoms in nonanemic patients. Four patients experienced transient neurologic exacerbations soon after beginning treatment with cyanocobalamin, with subsequent recovery. Followup evaluation was adequate to assess the neurologic response to vitamin B12 therapy in 121 episodes. All patients responded, and in 57 (47.1%), recovery was complete, with no remaining symptoms or findings on examination. The severity score was reduced by 50% or greater after treatment in 91% of the episodes. Residual long-term moderate or severe neurologic disability was noted following only 7 (6.3%) episodes. The extent of neurologic involvement after treatment was strongly related to that before therapy as well as to the duration of symptoms. The percent improvement over baseline neurologic status after treatment was inversely related to duration of symptoms and hematocrit. Some evidence of response was always seen during the first 3 months of treatment.(ABSTRACT TRUNCATED AT 400 WORDS)

Neuropsychiatric disorders caused by cobalamin deficiency in the absence of anemia or macrocytosis

Among 141 consecutive patients with neuro-psychiatric abnormalities due to cobalamin deficiency, we found that 40 (28 percent) had no anemia or macrocytosis. The hematocrit was normal in 34, the mean cell volume was normal in 25, and both tests were normal in 19. Characteristic features in such patients included paresthesia, sensory loss, ataxia, dementia, and psychiatric disorders; longstanding neurologic symptoms without anemia; normal white-cell and platelet counts and serum bilirubin and lactate dehydrogenase levels; and markedly elevated serum concentrations of methylmalonic acid and total homocysteine. Serum cobalamin levels were above 150 pmol per liter (200 pg per milliliter) in 2 patients, between 75 and 150 pmol per liter (100 and 200 pg per milliliter) in 16, and below 75 pmol per liter (100 pg per milliliter) in only 22. Except for one patient who died during the first week of treatment, every patient in this group benefited from cobalamin therapy. Responses included improvement in neuropsychiatric abnormalities (39 of 39), improvement (often within the normal range) in one or more hematologic findings (36 of 39), and a decrease of more than 50 percent in levels of serum methylmalonic acid, total homocysteine, or both (31 of 31). We conclude that neuropsychiatric disorders due to cobalamin deficiency occur commonly in the absence of anemia or an elevated mean cell volume and that measurements of serum methylmalonic acid and total homocysteine both before and after treatment are useful in the diagnosis of these patients.

Reversible ocular toxicity related to tamoxifen therapy

A 42-year-old woman with metastatic breast cancer developed bilateral optic disc swelling, retinal hemorrhages, and visual impairment three weeks after starting treatment with low doses of tamoxifen. Neurologic evaluation failed to provide an explanation for the ocular findings which resolved completely after cessation of tamoxifen therapy. This case suggests that tamoxifen has the potential for causing serious ophthalmologic toxicity which may be reversible if recognized early.

Oncology clinic attendance at an inner city hospital

Compliance in oncology clinic attendance was prospectively evaluated over a 12-month period at Harlem Hospital Center, an inner city municipal facility serving a predominantly black population. One hundred patients were followed (97 blacks, 2 Hispanics, 1 white) with an average age of 60 years. There were 41 men and 59 women. Thirty-one patients had breast cancer, 23 lung cancer, 26 miscellaneous solid tumors, and 20 hematologic malignancies. Forty-two patients received chemotherapy, 14 hormonal therapy, and 44 supportive care alone. Of the 657 appointments scheduled for the total group, 583 (89%) were kept. All scheduled appointments were kept by 53% of patients and 80% or more were kept by 69% of patients. There was no statistically significant difference in clinic attendance according to sex, age younger than 50 years, tumor category, or mode of therapy. Reasons for missing appointments included the patient forgot or was confused (7 cases), weather (5), transportation difficulties (5), clerical error (3), and refusal of further chemotherapy (1). A high rate of clinic attendance is reported in this group of patients with multiple social and financial problems. Such patients are appropriate candidates for treatment protocols requiring frequent clinic visits.

Multiple myeloma masquerading as metastatic breast cancer

Two women are described in whom, on the basis of prior therapy for breast cancer and the presence of painful, lytic bone lesions, an initial diagnosis of metastatic breast cancer was made. Further evaluation established the diagnosis of multiple myeloma in both patients. Neither had evidence of recurrent breast cancer. These cases indicate that women with a history of breast cancer in whom lytic bone lesions develop without evidence of extraskeletal metastases should have the diagnosis of multiple myeloma excluded.

Kaposi's sarcoma in heterosexual intravenous drug users

Kaposi's sarcoma is a feature of the acquired immunodeficiency syndrome (AIDS) in male homosexuals and Haitians. In this report the authors describe six heterosexual intravenous drug users who developed Kaposi's sarcoma. They had other characteristics of AIDS including opportunistic infections (oral candidiasis, six patients; Pneumocystis carinii pneumonia, two patients; genital herpes simplex, two patients; disseminated cytomegalovirus, one patient; Mycobacterium avium, one patient) and inversion of the normal ratio of helper-suppressor T-cell subsets in peripheral blood lymphocytes in the two patients in whom it was determined. These observations indicate that intravenous drug users as well as Haitians and homosexual men are at risk for developing Kaposi's sarcoma as part of the acquired immunodeficiency syndrome.

Race, poverty, and survival in multiple myeloma

To identify possible interracial differences in the behavior of multiple myeloma, the records of 52 black myeloma patients at Harlem Hospital Center (HHC) and 46 black and 46 white patients at Columbia-Presbyterian Medical Center (CPMC) were reviewed. In addition to clinical variables such as tumor burden, azotemia, and hypoalbuminemia, the effect of poverty on prognosis was examined, using socioeconomic indices from the United States census block group data of each patient. The median survival of CPMC black and white patients was comparable (34 and 29 months, respectively) whereas that of the HHC group was 12 months (Breslow test, P less than 0.0001). Overcrowding and hypoalbuminemia were the most significant prognostic factors by multivariate regression analysis on all 144 patients (P = 0.001); for HHC patients, overcrowding was the single significant variable affecting survival (P = 0.004). By all socioeconomic indices, HHC patients were more impoverished than CPMC patients (P less than 0.001); they also presented with more advanced disease. Race is not a significant prognostic factor in myeloma, whereas the effect of socioeconomic status on survival appears to equal that of previously described clinical features.

Biphasic pattern of bacterial infection in multiple myeloma

Since the 1960s, gram-negative bacilli have become commoner pathogens than Streptococcus pneumoniae in multiple myeloma. To investigate this trend, we analyzed 75 bacterial infections in 57 patients with myeloma. Episodes of infection with Streptococcus pneumoniae and Haemophilus influenzae occurred at presentation, early in the disease, and in patients responding to chemotherapy. Gram-negative bacilli and Staphylococcus aureus caused 80% of infections seen after diagnosis and 92% of deaths from infection. Episodes of infection with gram-negative bacteria occurred in patients with active and advancing disease and in those responding to chemotherapy when neutropenia. Impaired antibody production may be the major immune defect leading to S. pneumoniae and H. influenzae infections whereas some additional factor or factors related to disease activity appear to predispose to gram-negative infection in myeloma.

Fatal graft-versus-host disease following blood transfusion in Hodgkin's disease documented by HLA typing

Fatal graft-versus-host disease (GVHD) developed in a patient with Hodgkin's disease treated with combined chemotherapy and radiotherapy following the transfusion of 2 U of packed red blood cells. Clinical features of the GVHD included the development of exfoliative dermatitis, progressive hepatic dysfunction, aplastic anemia, and finally progressive fatal pneumonia. GVHD was documented by skin biopsy and chimerism by HLA typing. The HLA phenotype of the patient's skin fibroblasts [A3, Bw44 (w4)/A2, B15 (w4)] was appropriate for parental haplotypes and probably represented her true HLA phenotype. Lymphocytes from the patient (peripheral blood and lymph node biopsy) were of a different HLA phenotype (A3; Bw35, w38, w4, w6; Cw4), which was inappropriate for parental HLA haplotypes but identical to the HLA phenotype of one of the blood donors. The HLA-DR typing of the patient's family and of the blood donor demonstrated that the patient and the donor probably were HLA-DR identical (DRw5/DRw6), although no B lymphocytes could be obtained from the patient for direct DR typing. We are currently irradiating all blood products administered to patients with Hodgkin's disease receiving intensive treatment. Further observations will be necessary to determine whether transfusions to other cancer patients with immunodeficiency states should be restricted to irradiated blood products.

Bone marrow transplantation for the therapy of refractory adult T cell acute lymphoblastic leukemia

Two adult patients with T cell acute lymphoblastic leukemia (ALL) received an intensive multiagent therapeutic regimen and failed to enter remission. Following cytoreduction with cyclophosphamide (60 mg/kg x 2) and total body irradiation (1000 rads) they underwent bone marrow transplantation. One patient received marrow from his identical twin brother and the other from his HLA-matched sister. Both patients promptly went into remission. The identical twin recipient is alive and free of disease at 20+ months, but the allogeneic patient died of P. carinii pneumonia at eight months with no evidence of leukemia. These results suggest that even some refractory patients whose disease has multiple negative prognostic features may respond to pretransplant chemoradiotherapy and attain a clinically useful complete remission. Additional patients with longer follow-up will be necessary before the curative potential of bone marrow transplantation in T cell ALL can be assessed.

Detection of antibody to autologous human leukemia cells by immune adherence assays

The sera of 21 adult patients with acute leukemia were studied for the presence of antibody reacting with surface antigens of autologous leukemia cells. Sequential serum samples were obtained from patients and were tested on cryopreserved leukemia cells in immune adherence assays. Three patients showed autologous serum reactivity and the serum of one of them was analyzed in detail. This antibody reacted with autologous acute lymphocytic leukemia cells but not with autologous cells obtained from peripheral blood, bone marrow, or spleen during clinical remission. In absorption tests, the antigen could not be detected on normal autologous or allogeneic blood lymphocytes, lymphoblastoid lines of T- or B-cell origin, or cells infected with simian sarcoma virus, baboon C-type virus, or Mason-Pfizer virus. Leukemia cells from two other patients with acute lymphocytic leukemia and one patient with acute nonlymphocytic leukemia absorbed specific reactivity. These studies indicate that certain acute leukemia cells express a common antigen that elicits a humoral immune response in the autologous host.