RNA transcription and lysosomal activation during xenotransplant hyperacute rejection: inhibition of RNA polymerase

In summary, our data indicates that AFB1 has no effect on LyAct during XTHAR. Although these results are from short-term incubation studies, they nevertheless suggest that inhibition of RNA transcription by AFB1 may be of no consequence in LyAct during XTHAR. Hence, our results appear to support the view that, in general, XTHAR recruits preformed components and may not require de novo synthesis of lysosomal proteins. Additional studies using long-term incubation (days to weeks) and other protein synthesis blockers are suggested to further elucidate the effects of protein synthesis inhibition of LyAct during XTHAR.

Ethnic variations in lung cancer

Cancer of the lung is the most frequent cancer in the world, but with wide geographical variation in risk. It is most spread among males of all races worldwide, the only exception being its incidence among Chinese women aged 70 years and older. When comparing the different ethnic groups we have to consider that besides inhaling cigarette smoke actively or as a passive smoker the exposure to occupational carcinogens varies considerably according to different work places. In our study we compared 10 years of data from African-Americans in Howard University Hospital, Washington D.C. with 20 years of data from the white population in the University Hospital of Vienna, Austria. Ethnic patterns are generally consistent within each group in terms of both incidence and mortality. The difference in susceptibility between the sexes, the three major racial groups and already proven differences in genetic variations indicate the difference between individuals concerning the initiation and progression of lung cancer.

Racial variation in lung cancer

Lung cancer claimed about 153,000 lives in 1994 in the United States. Despite research overall lung cancer survival has still not improved during the last 20 years, with 5-year relative survival remaining about 13%. In addition several epidemiologic and molecular studies showed a difference in the incidence of lung cancer in the three major races. The aim of our study was to investigate the variations of race in lung cancer patients, in order to identify potential risk factors linked to the different racial status. In this light we compared a 10 years lung cancer data of black population from Howard University Hospital, Washington D.C., U.S.A. and a 20 years data of white population from the Vienna University Hospital, Austria. Our results did not show any significant difference in mean age or tumor localization in both groups, but highlighted a remarkable difference in the incidence of the lung cancer histological types also according to the sex. In this respect it could be more successful to consider carcinogenesis like a protracted process of gene function deregulation in response to cell injury from exposure to genotoxic substances with individual specificity.

Gastric carcinoma in African Americans: a 10 year single center analysis

The occurrence of gastric cancer (GCa) has been declining in the U.S. over the past years. The reasons for this decline, though unclear, may not hold true for minorities. In fact, data on the occurrence, presentation and determinants of survival in African Americans still remains sketchy. In an attempt to rectify this problem, we retrospectively analyzed accumulated data at the Howard University Cancer Center between 1985 and 1994. There were 115 patients with GCa, 53 females and 62 males. The age range was 26-88 years, with most patients being over 50 years of age (84%). Eighty seven out of the 115 patients were completely staged and thus formed the population base for the analysis. There was a progressive decline in the frequency of diagnosis of GCa between the 1985-1989: 63% cases (55/87) and 1990-1994: 37% cases (32/87). In analyzing this group, we found no gender difference on presentation. Seventy percent of the patients (61/87) presented with the advanced disease (stages III & IV). Eighty eight percent (77/87) underwent surgery: 50/77 surgery alone; 9/77 surgery and chemo; 18/77 surgery and other forms of therapy (radiotherapy and chemotherapy). Seventy one percent of the patients who presented with late stage disease, died within 12 months. The predominant histologic type was adenocarcinoma (85%), while lymphoma and leiomyosarcoma accounted for five and three percent respectively. In conclusion, our data suggest that most patients in our minority population presented at a late stage of GCa, and stage was an important determinant of survival. Also, our findings are in agreement with the declining trend of GCa in the U.S.

Splenectomy in cancer surgery: diminishing indications?

The diminishing enthusiasm towards performing splenectomy (SPL) either as an integral part of surgical cancer management (SCM), or for staging/management (ST) of lymphoma, warranted our assessment of the extent of this trend in a minority population. We retrospectively analysed all SPL submitted to Surgical Pathology for histological processing over a 24-year period (1/1/70-12/31/93) at the Howard University Hospital, a predominantly African-American institution. Of the 446 SPL performed during the period, sixty-nine (15.5%) were performed as part of SCM/ST. Seventy-five per cent (52/69) were for solid intra-abdominal cancers (SIC) and 25% (17/69) for lymphoma. As a group, the patients were older, 71% over 40 years old) and showed a male predominance (61% males). Sixty-two per cent (43/69) of the SPL were performed in the decade 1970-1979. In the following decade 1980-1989, the frequency with which SPL was performed, had dropped to 33% (23/69). Four years into the current decade, 1990-1993, only 5% (3/69) of the SPL were performed for SCM/ST. These findings suggest that in African-Americans, the performance of SPL in ST/SCM has been declining over the years, which is in agreement with the current growing trends in cancer treatment i.e. to avoid unnecessary operations, limit morbidity, preserve important organs, maintain immunocompetence of the patient and to utilize advanced imaging techniques in ST/SCM.

Post-transplant malignancies in minority populations

Post-transplant malignancy (PTM), is emerging as an important cause of early morbidity and mortality following transplantation (TX). Unfortunately its prevalence in minorities (African-Americans, AA; Native Americans, NA; Asian Pacific Islanders, AP; American Indians, AI; Latino-Hispanics, LH) in the United States, though important, remains unknown. Published reports of prevalence rates by different centers, including the Cincinnati Transplant Tumor Registry (CITTR) of about 4%-18% though informative, remain of little help. These reports erroneously assume a homogeneity in population, uniformity in the impact and spread of the determinants of this disease, and equal access to health for all patients. Data from AA, the only minority group studied by the Howard University Hospital Transplant Center (HUHTC) group, in Washington, D.C.; revealed a cancer occurrence of 3% in 339 TX patients. It is important to note that unlike the CITTR data base, the HUHTC cancer database is smaller. Nevertheless, a comparative analysis was revealing. Skin/lymphoid cancers had a lower occurrence (20% versus 54%), while head and neck tumors had a higher occurrence (30% versus 3%) as were genitourinary cancers (30% versus 8%) in AA as compared to the general population. Since minorities as a group are prone to higher cancer prevalence and mortality rates, and because patterns of PTM may differ among groups, studies to analyze PTM and other factors that may further escalate cancer rates in minorities deserve greater impetus.

Spontaneous rupture of the renal allograft

Spontaneous renal allograft rupture, an unusual complication of renal transplantation, occurred in a 35-year-old woman 10 days after transplantation. Unusual localized pain and tenderness at allograft site, oliguria, and hypotension, a triad frequently seen in renal allograft rupture, were present. Management by transplant nephrectomy was inevitable because of the patient's downhill course. Histopathologic findings diagnostic of acute allograft rejection support current thinking that spontaneous rupture may be the final outcome, although unusual, of renal allograft rejection.

Tracheopleuropulmonary injuries following enteral tube insertion

Eighty-three cases of tracheopleuropulmonary injuries complicating enteral tube feeding are analyzed to identify the patterns of injury, and precipitating factors and ways to avoid them. Six new cases observed by the authors and 77 other cases cited in British literature between 1976 and 1987 are presented. In recent years, reports of this complication have been increasing, apparently in a geometrical progression: 8%, 18%, and 74% were reported between 1976 to 1979, 1980 to 1983, and 1984 to 1987, respectively. Sixty-one percent occurred in patients aged 60 years or older. Most of the patients (84%) were seriously ill, which compounded their complications. Seventy-four percent of all injuries were committed by house staff; the narrow bore tube with guide wire was used in 77% of cases. Less than reliable methods were used to confirm tube position in most instances. The presence of cuffed endotracheal tubes did not offer protection. The patients on mechanical ventilation tended to deteriorate if they developed a pneumothorax once the malpositioned tubes were removed. Of the cases reviewed for this report, 18 deaths occurred; 72% being directly related to the tube injuries. Lack of awareness, inadequate confirmatory methods, and insufficient supervision accounted for most of these preventable complications. Educating house/nursing staff in the use of the new tubes, closer supervision, and the application of equal measures of care and caution as employed in other invasive and potentially dangerous procedures are recommended to avoid disastrous outcome.