The China Productivity Project: results and conclusions.

Experiments were conducted to determine what factors cause variation in individual work output (economic productivity). Forty-five young male Chinese cycle haulers from Beijing were assessed for physiological work capacity, size and body composition, health, nutritional status, cold resistance, household social environment, and motivation. Experiments were conducted in the laboratory as well as under actual working conditions; ethnographic observations were made in the household and on the job during the Beijing winter of 1992. Overall work motivation correlated to actual monthly distance/load measures of productivity the most strongly (r = 0.518), followed by physiological capacity estimated by heart rate:speed ratio during field experiments (r = -0.473). Alcohol consumption (a negative factor), household health, and carbohydrate intake were all moderate predictors. Maximum oxygen uptake showed lower correlation (r = 0.261), and among anthropometric values only relatively long lower legs were predictive (r = 0.298). Since many of these variable categories were relatively independent of each other, multiple regression analysis showed that together they explained 61.6% of the work output variance. Simultaneous prediction by FASEM (LISREL) is also very strong.

Work performance of Chinese cycle haulers: controlled field experiments in normal work conditions.

Forty-five male Chinese cycle haulers performed a controlled field experiment under mild winter conditions. The objective was to gain insight into factors that affect work performance. Each man hauled the same 481-kg load around a Beijing street course of 14.18 km. The experiment was a measured sample of the same work they do routinely, on the same roads, using similar human powered hauling cycles (modified only enough to carry observers and instruments). The course was completed at a mean speed of 10.4 kph and mean time of 84.2 min. While there was considerable variation in individual pace and in pace change during work, the haulers performed at relatively high output in reference to their capacities. Mean heart rate was 156.8 +/- 16.1 bpm, 83.9% of maximum. The men had average body build and were average in size for the general Chinese population (X stature = 169.7 cm) although they showed relatively high aerobic capacity (determined in laboratory tests). Performance levels during experiments appear to match habitual work patterns, and self-pacing emerged as a major behavioral finding of this research. Speed, a primary index of job performance, showed significant correlation to heart rate, VO2max, variation in windchill, self-reported health and other variables, with a multiple regression coefficient of 0.811. Similar patterns were seen for heart rate relative to speed, except that physical size, education, and other behavioral variables were also predictors.

High-dose mitomycin-C with autologous bone marrow transplantation in patients with refractory malignancies. Influence of dose schedule on pharmacokinetics and nonhematopoietic toxicities.

Thirteen courses of high-dose mitomycin-C with autologous bone marrow transplantation (ABMT) were administered to 12 patients. Four dose schedules were evaluated: A) 60 mg/M2 X 1, 60-min infusion; B) 30 mg/M2/day X 2, 15-min infusion; C) 30 mg/M2/day X 2, 60-min infusion; D) 15 mg/M2/day X 4, 60-min infusion. Pharmacokinetic studies using HPLC technique were done in nine patients. All patients have since died and autopsies were performed in nine patients. Two major nonhematopoietic toxicities were encountered and were dose-schedule dependent: hemorrhagic colitis (six of six courses in Schedules A and B; two of seven in Schedules C and D), and hepatic dysfunction (five of six in Schedules A and B; two of seven in Schedules C and D). Histopathologic evidence of venocclusive disease of the liver was present in four of five autopsies in Schedules A and B, and two of four in Schedules C and D. One patient died as a result of liver failure associated with submassive hepatic necrosis. Saturation kinetics described by other investigators cannot be confirmed by our pharmacokinetic analyses in nine patients. Severe nonhematopoietic toxicities of mitomycin-C were found at three times the conventional dose; thus, this drug is assessed as not being clinically useful as a single agent in ABMT.

Prevention of infection on the oncology unit.

Various combinations of immune deficiency, tumor effect, surgery, ionizing radiation, chemotherapy, and neutropenia result in infection-prone states for hospitalized cancer patients. Recognition of nosocomial infection may be difficult, and fever may be the only finding. Pathogens may be exogenously acquired from the contaminated hospital environment. Transmission by contact with hospital personnel is the usual mode of exogenous acquisition of hospital bacteria, and handwashing is the most effective means of prevention. The utility of conventional protective isolation in prevention of exogenous transmission is in question. Inattention to infection control measures by nurses and physicians may result in higher infection rates and more serious types of infections. Endogenous infection by the patient's own bacteria and fungi also occurs in the cancer ward. Autoinfection is "amplified" by the use of cannulae, catheters, and other hospital devices. Meticulous nursing care, particularly in neutropenic persons, is important in reducing the incidence of endogenous spread of microbes. Exogenous and endogenous infections in neutropenic patients are reduced using laminar air flow rooms combined with prophylactic antibiotics. It is still not clear if these expensive measures are effective in prolonging survival of patients with acute leukemia.