Charles R. Goldman

Laparoscopic Versus Open Gastric Bypass: A Randomized Study of Outcomes, Quality of Life, and Costs

ObjectiveTo compare outcomes, quality of life (QOL), and costs of laparoscopic and open gastric bypass (GBP). Summary Background DataLaparoscopic GBP has been reported to be a safe and effective approach for the treatment of morbid obesity. The authors performed a prospective randomized trial to compare outcomes, QOL, and costs of laparoscopic GBP with those of open GBP. MethodsFrom May 1999 to March 2001, 155 patients with a body mass index (BMI) of 40 to 60 kg/m2 were randomly assigned to undergo laparoscopic (n = 79) or open (n = 76) GBP. The two groups were similar in age, sex ratio, mean BMI, and comorbidities. Main outcome measures included operative time, estimated blood loss, length of hospital stay, operative complications, percentage of excess body weight loss, and time to return to activities of daily living and work. Changes in QOL were assessed using the SF-36 Health Survey and the bariatric analysis of reporting outcome system (BAROS). Operative and hospital costs of the two operations were also compared. ResultsThere were no deaths in either group. Mean operative time was longer for laparoscopic GBP than for open GBP, but operative blood loss was less. Two (2.5%) of the 79 patients in the laparoscopic group required conversion to laparotomy. Median length of hospital stay was shorter for laparoscopic GBP patients (3 vs 4 days). The rate of postoperative anastomotic leak was similar between groups. Wound-related complications such as infection (10.5 vs 1.3%) and incisional hernia (7.9 vs 0%) were more common after open GBP; late anastomotic stricture was less frequent after open GBP (2.6 vs 11.4%). Time to return to activities of daily living and work were shorter after laparoscopic GBP than after open GBP. Weight loss at 1 year was similar between groups. Preoperative SF-36 scores were similar between groups; however, at 1 month after surgery, laparoscopic patients had better physical conditioning, social functioning, general health, and less body pain than open GBP patients. At 6 months, the BAROS outcome was classified as good or better in 97% of laparoscopic GBP patients compared with 82% of open GBP patients. Operative costs were higher for laparoscopic GBP patients, but hospital costs were lower. ConclusionsLaparoscopic GBP is a safe and cost-effective alternative to open GBP. Despite a longer operative time, patients undergoing laparoscopic GBP benefited from less blood loss, a shorter hospital stay, and faster convalescence. Laparoscopic GBP patients had comparable weight loss at 1 year but a more rapid improvement in QOL than open GBP patients. The higher initial operative costs for laparoscopic GBP were adequately offset by the lower hospital costs.

A highly unsaturated fatty acid predicts carbon transfer between primary producers and consumers.

The factors that regulate energy transfer between primary producers and consumers in aquatic ecosystems have been investigated for more than 50 years (refs 1,2,3). Among all levels of the food web (plants, herbivores, carnivores), the plant–animal interface is the most variable and least predictable link. In hypereutrophic lakes, for example, biomass and energy transfer is often inhibited at the phytoplankton–zooplankton link, resulting in an accumulation of phytoplankton biomass instead of sustaining production at higher trophic levels, such as fish. Accumulation of phytoplankton (especially cyanobacteria) results in severe deterioration of water quality, with detrimental effects on the health of humans and domestic animals, and diminished recreational value of water bodies. We show here that low transfer efficiencies between primary producers and consumers during cyanobacteria bloom conditions are related to low relative eicosapentaenoic acid (20:5ω3) content of the primary producer community. Zooplankton growth and egg production were strongly related to the primary producer 20:5ω3 to carbon ratio. This indicates that limitation of zooplankton production by this essential fatty acid is of central importance at the pelagic producer–consumer interface.

Role of aquatic plants in wastewater treatment by artificial wetlands.

Abstract This report describes investigations using artificial wetlands which quantitatively assess the role of each of three higher aquatic plant types, Scirpus validus (bulrush), Phragmites communis (common reed) and Typha latifola (cattail), in the removal of nitrogen (via sequential nitrification-denitrification), BOD and TSS from primary municipal wastewaters. During the period August 1983–December 1984, the mean ammonia concentration of 24.7 mg l−1 in the primary wastewater inflow (hydraulic application rate = 4.7 cm day−1) was reduced to mean effluent levels of 1.4 mg l−1 for the bulrush bed, 5.3 mg l−1 for the reed bed and 17.7 mg l−1 for the cattail bed, as compared to a mean value of 22.1 mg l−1 for the unvegetated (control) bed. For all three vegetated beds, the mean effluent ammonia values were significantly below that for the unvegetated bed and for the inflow. The bulrushes and reeds (in that order) proved to be superior at removing ammonia, both with mean effluent levels significantly below that for the cattail bed. The high ammonia-N (and total N) removal efficiencies shown by the bulrush and reed beds are attributed to the ability of these plants to translocate O2 from the shoots to the roots. The oxidized rhizosphere so formed stimulates sequential nitrification-denitrification. Similarly BOD removal efficiencies were highest in the bulrush and reed beds, both with mean effluent BOD levels (5.3 and 22.2 mg l−1, respectively) significantly below that for the unvegetated bed (36.4 mg l−1) and equal to or better than secondary treatment quality (30 mg l−1). Our results demonstrate that higher aquatic plants can indeed play a significant role in secondary and advanced (N removal) wastewater treatment by wetland systems, a role that is completely distinct from that associated with their pollutant uptake capacity.

Comparison of pulmonary function and postoperative pain after laparoscopic versus open gastric bypass: A randomized trial

BACKGROUND Impairment of pulmonary function is common after upper abdominal operations. The purpose of this study was to compare postoperative pulmonary function and analgesic requirements in patients undergoing either laparoscopic or open Roux-en-Y gastric bypass (GBP). STUDY DESIGN Seventy patients with a body mass index of 40 to 60 kg/m2 were randomly assigned to undergo laparoscopic (n = 36) or open (n = 34) GBP. The two groups were similar in age, gender, body mass index, pulmonary history, and baseline pulmonary function. Pulmonary function studies were performed preoperatively and on postoperative days 1, 2, 3, and 7. Oxygen saturation and chest radiographs were performed on both groups preoperatively and on postoperative day 1. Postoperative pain was evaluated using a visual analog scale and the amount of narcotic consumed was recorded. Data are presented as mean +/- standard deviation. RESULTS Laparoscopic GBP patients had significantly less impairment of pulmonary function than open GBP patients on the first three postoperative days (p < 0.05). By the 7th postoperative day, all pulmonary function parameters in the laparoscopic GBP group had returned to within preoperative levels, but only one parameter (peak expiratory flow) had returned to preoperative levels in the open GBP group. On the first postoperative day, laparoscopic GBP patients used less morphine than open GBP patients (46 +/- 31 mg versus 76 +/- 39 mg, respectively, p < 0.001), and visual analog scale pain scores at rest and during mobilization were lower after laparoscopic GBP than after open GBP (p < 0.05). Fewer patients after laparoscopic GBP than after open GBP developed hypoxemia (31% versus 76%, p < 0.001) and segmental atelectasis (6% versus 55%, p = 0.003). CONCLUSION Laparoscopic gastric bypass resulted in less postoperative suppression of pulmonary function, decreased pain, improved oxygenation, and less atelectasis than open gastric bypass.

Unsaturated fatty acid content in seston and tropho-dynamic coupling in lakes

Determining the factors that control food web interactions is a key issue in ecology. The empirical relationship between nutrient loading (total phosphorus) and phytoplankton standing stock (chlorophyll a) in lakes was described about 30 years ago and is central for managing surface water quality. The efficiency with which biomass and energy are transferred through the food web and sustain the production of higher trophic levels (such as fish) declines with nutrient loading and system productivity, but the underlying mechanisms are poorly understood. Here we show that in seston (fine particles in water) during summer, specific ω3-polyunsaturated fatty acids (ω3-PUFAs), which are important for zooplankton, are significantly correlated to the trophic status of the lake. The ω3-PUFAs octadecatetraenoic acid, eicosapentaenoic acid (EPA) and docosahexaenoic acid, but not α-linolenic acid, decrease on a double-logarithmic scale with increasing total phosphorus. By combining the empirical relationship between EPA-to-carbon content and total phosphorus with functional models relating EPA-to-carbon content to the growth and egg production of daphnids, we predict secondary production for this key consumer. Thus, the decreasing efficiency in energy transfer with increasing lake productivity can be explained by differences in ω3-PUFA-associated food quality at the plant–animal interface.

Nitrogen removal in artificial wetlands

Abstract This report describes investigations which have demonstrated the exceptional utility of artificial wetlands for the removal of nitrate from secondary wastewater effluents at relatively high application rates. The artificial wetlands (14 in number) were plastic-lined excavations containing emergent vegetation growing in gravel. Without supplemental additions of carbon, total nitrogen removal efficiency was low (∼ 25%) in both vegetated and unvegetated beds. When methanol was added to supplement the carbon supply and stimulate bacterial denitrification, the removal efficiency was extremely high (95% removal of total nitrogen at a wastewater application rate of 16.8 cm day−1). Since methanol is a relatively expensive form of carbon, we tested the feasibility of using plant biomass, mulched and applied to the surface of marsh beds, as an alternate source of carbon. At a wastewater application rate of 8.4 cm day−1, the mean total nitrogen removal efficiency for the mulch-amended beds was 86%. When the application rate was higher (16.8 cm day−1) the mean total nitrogen removal efficiency was lower, 60% in the mulch-amended beds. By using plant biomass as a substitute for methanol, the energy savings for a treatment facility serving a small community (3785 m3 day−1 or 1 mgd) would amount to the equivalent of 731 day−1 of methanol. As the cost of fossil fuel increases, energy cost will become a predominant factor in the selection of small (0.5–5 mgd) wastewater treatment systems. However, in many cases where natural wetlands are either geographically unavailable or protected from wastewater discharge by environmental, legal, or aesthetic restraints, artificial wetlands offer a viable alternative for energy-effective treatment of municipal and agricultural wastewater effluents.

Historical Food Web Structure and Restoration of Native Aquatic Communities in the Lake Tahoe (California-Nevada) Basin

Plans for the restoration of aquatic ecosystems are increasingly focusing on the restoration and rehabilitation of self-sustaining native fish communities. Such efforts have not traditionally adopted an ecosystem-based perspective, which considers species as embedded within a broader food web context. In this study, we quantify food web changes in Lake Tahoe (California-Nevada) over the last century based on stable isotope analysis of museum-archived, preserved fish specimens collected during 4 historical periods and under present conditions. We also examine the contemporary food web of nearby Cascade Lake, which is free from most exotic species and contains a species assemblage resembling that of Lake Tahoe prior to historical species introductions. During the last century, the freshwater shrimp Mysis relicta and lake trout (Salvelinus namaycush) have been introduced and established in Lake Tahoe, and the native top predator, Lahontan cutthroat trout (Oncorhynchus clarki henshawi; hereafter LCT), has been extirpated. Isotope analysis indicates that lake trout now occupy a trophic niche similar to that of historical LCT. Fish production has shifted from benthic to pelagic, corresponding with the eutrophication of Lake Tahoe during recent decades. The current Cascade Lake food web resembles that of the historical Lake Tahoe food web. Our isotope-based food web reconstructions reveal long-term food web changes in Lake Tahoe and can serve as the basis for setting historically relevant restoration targets. Unfortunately, the presence of nonnative species, particularly Mysis and lake trout, have dramatically altered the pelagic food web structure; as such, they are barriers to native fish community restoration. Fish community restoration efforts should focus on adjacent ecosystems, such as Cascade Lake, which have a high likelihood of success because they have not been heavily affected by nonnative introductions.

Atmospheric deposition of nitrogen and phosphorus in the annual nutrient load of Lake Tahoe (California-Nevada)

Atmospheric deposition provides most of the dissolved inorganic nitrogen (DIN) and total nitrogen in the annual nutrient load of Lake Tahoe. Deposition also contributes significant amounts of soluble reactive phosphorus (SRP) and total phosphorus loading but plays less of a role than in the case of nitrogen. Most of the DIN probably originates outside of the drainage basin in urban and agricultural areas to the south and west. Spatial patterns of SRP deposition differ from those of DIN and suggest a within-basin terrestrial source, such as leachate from windblown dust or other particles. Because of atmospheric N deposition, the N:P (molar) ratio in combined loading is well above the Redfield ratio of 16 and consistent with an observed shift from colimitation by N and P to persistent P limitation in the lake phytoplankton.

Primary Productivity and Limiting Factors in Three Lakes of the Alaska Peninsula

INTRODUCTION The lakes draining into Bristol Bay along the base of the Alaska Peninsula are nurseries for juveniles of the red salmon (Oncorhynchus nerka [Walbaum]) spawned in the lake tributaries. Other Alaskan Pacific salmons are also taken in the coastal fishery, but the reds (also called sockeyes or bluebacks) contribute most to making the local fishery one of the most valuable in the world. Fluctuations from year to year in the abundance of the red salmon have prompted many investigations, yet various aspects of its ecology remain imperfectly understood. This investigation was planned to measure and compare the primary productivity of certain red salmon nursery lakes, and determine what factors were limiting. The opportunity to make the study arose through the interest of the United States Fish and Wildlife Service in ecological factors that affect the numbers and condition of young of this important species. Field work was conducted from the Brooks Lake Research Station, established in 1940, which provided living quarters and laboratory facilities. It is supplied primarily by amphibious aircraft. The principal objective of the Station is to determine how physical, chemical, and biological factors affect populations of red salmon in fresh waters. Considerable evidence suggests that the abundance of this salmon is determined by conditions during its early life in fresh water (Barnaby 1944). Its growth in fresh water, although only a fraction of that achieved in the sea, is of great importance in determining the percentage of a given year class that reaches sexual maturity (Foerster 1954). That food supply is a limiting factor in some drainage systems is sug-

Distribution, density and production of the crayfish Pacifastacus leniusculus Dana in Lake Tahoe, California - Nevada

The standing crop of the California crayfish Pacifastacus leniusculus (Dana) is concentrated in the narrow littoral zone of Lake Tahoe and is estimated by trapping returns at 55.5 million adults weighing 1,100,000 kg. The population density differs in relation to substrata and local eutrophication with an average of about 0.9 adults per M2. A more eutrophic area of the lake yielded over twice as many crayfish per trap as less productive areas. Maximum density is found between 10 and 20 m withover 900, of the population found between 0 and 40 m of depth. Because the average depth of Tahoe is 313 m this represents only 12 %? of the lake surface area. Wave action and light appears to limit crayfish density above 10 m depth and water temperature below 40 m. The temperature distribution factor is supported by an experiment where females held at an average of 6.8 C failed to hatch eggs. Substrata which provide good protection from predators produce larger numbers of smaller individuals while more open areas of the lake bottom have a smaller number and larger individuals. Between 80 and 100 % of the population over 95 mm in length are sexually mature. Females carry an average of 1 10 eggs.