The urban stormwater farm.

Currently more than 3 billion people live in urban areas. The urban population is predicted to increase by a further 3 billion by 2050. Rising oil prices, unreliable rainfall and natural disasters have all contributed to a rise in global food prices. Food security is becoming an increasingly important issue for many nations. There is also a growing awareness of both 'food miles' and 'virtual water'. Food miles and virtual water are concepts that describe the amount of embodied energy and water that is inherent in the food and other goods we consume. Growing urban agglomerations have been widely shown to consume vast quantities of energy and water whilst emitting harmful quantities of wastewater and stormwater runoff through the creation of massive impervious areas. In this paper it is proposed that there is an efficient way of simultaneously addressing the problems of food security, carbon emissions and stormwater pollution. Through a case study we demonstrate how it is possible to harvest and store stormwater from densely populated urban areas and use it to produce food at relatively low costs. This reduces food miles (carbon emissions) and virtual water consumption and serves to highlight the need for more sustainable land-use planning.

Release of kallikrein from guinea pig lung during anaphylaxis.

An antigen-antibody reaction occurring in the perfused sensitized guinea pig lung, has been demonstrated to release kallikrein, a proteolytic enzyme related to the formation of kinins. This lung kallikrein is similar to plasma kallikrein in all properties studied, including susceptibility to the same inhibitors, electrophoretic mobility, and heterogeneity in molecular size. The release of kallikrein during anaphylaxis in the guinea pig lung occurs in the presence of ethylenediaminetetraacetate. Perfusion of ellagic acid into nonsensitized lungs will also release kallikrein, presumably through activation of Hageman factor. On the basis of these findings the hypothesis is suggested that the kallikrein in perfused lung activated by the antigen-antibody reaction is, in fact, plasma kallikrein. It is further suggested that activation of such kallikrein by the antigen-antibody reaction proceeds through Hageman factor.

Fetal islet allotransplantation in rabbits.

Haploidentical fetal rabbit islets were transplanted into the renal subcapsular space of outbred maternal hosts. Islets were prepared by a mild collagenase digestion and were cultured in air and a high oxygen environment for 10 days prior to implantation. Grafts were examined at 14 days and later. No grafts survived in the absence of host immunosuppression, even when treatment of the donor tissue included both culture and ultraviolet-B irradiation (groups 1 and 3). With a high dose of oral cyclosporine, 30 mg/kg/day on days 0-3, viable but disrupted islets were present in 1/7 recipients of islets treated by culture alone. Only with high-dose peritransplant cyclosporine or chronic low-dose immunosuppression, and islet treatment with UVB and culture, was regular graft survival achieved (groups 4A and 5). These results demonstrate that haploidentical outbred hosts can be made to accept fetal islet allografts pretreated by UVB irradiation and culture in a high oxygen environment only if the recipient is given a high peritransplant dose of oral cyclosporine (30 mg/kg/day) or chronic low-dose cyclosporine, (10 mg/kg/day).

The relationship between flow cytometer crossmatch results and subsequent rejection episodes in cadaver renal allograft recipients.

Flow cytometry (FC) T and B cell crossmatches were done retrospectively for 38 cadaver renal transplant recipients (29 first and 9 retransplants--minimum follow-up 12 months) using both current pretransplant serum and peak-reactive sera. An increase in median fluorescence intensity (channel shift) and/or an increase in the number of donor T and/or B cells binding antibody in test sera occurred in 23 cases. These 23 patients experienced a greater number of reversible rejection episodes as compared with patients with negative FC crossmatches (65% vs. 33%), P = 0.031. Graft outcome, however, was not different in the two groups. Thus, a positive FC crossmatch allows for the detection of subliminal levels of donor presensitization and is associated with a greater number of rejection episodes. A positive FC crossmatch is not predictive of ultimate graft loss.

Evidence that HLA class II disparity is required for the induction of renal allograft enhancement by donor-specific blood transfusions in man.

We studied 46 living-related primary renal allograft recipients between June 1980 and Jan 1988 to determine if enhancement of allograft survival by donor specific transfusions requires a major histocompatibility complex mismatch between the blood/kidney donor and the recipient. Recipients were matched for a single HLA haplotype, but differed at various HLA loci on the unshared haplotype. DST (200 ml) was administered either 3 times at two-week intervals pretransplant (n = 17), or once 3-4 weeks pretransplant, together with oral azathioprine (1 mg/kg/day/28 days) (n = 29). Patients were followed for at least 1 year and all clinical rejection episodes were confirmed histologically. Enhanced graft survival by DST was defined as a rejection-free posttransplant course. Incompatibility for class II determinants on the unshared haplotype of donor had a beneficial effect. A significantly greater proportion of recipients had stable, rejection-free, allograft function if incompatible for the DR locus (80% vs. 44%, P = 0.012), for class II public determinants (100% vs. 58%, P = 0.013), or for at least one of the class II gene products (DR, DQ, class II public) (81% vs. 40%, P = 0.006). Graft loss occurred in 7 of 46 (15%); 6 of the 7 recipients were HLA class II-compatible with their blood/kidney donor. Mismatches for HLA class I private or public determinants and other factors known to affect graft outcome did not influence the results. We conclude that enhanced kidney allograft survival by DST may be predicated by factors within the MHC--specifically class II disparity. These observations also suggest that better HLA matching at the class II locus may account for the apparent "disappearance" of the transfusion effect in cadaver renal transplants in the cyclosporine era.

Serious wound infections in burned patients.

Wound infections are a major problem in burned patients. To determine the rate of wound infection associated with initial wound size and the amount of open full-thickness wound, we prospectively studied all patients admitted within 1 week of burn injury during a 2-year period using weekly wound cultures. Wounds were treated with topical silver sulfadiazine and occlusive dressings. Burn wound excision and immediate grafting were initiated during the first postburn week. One thousand five hundred twenty-three patient weeks (483 patients) were evaluated. Serious burn wound infections developed during 55/185 patient weeks (42.3%) when the initial total burn (ITB) was greater than 40% body surface area (BSA). This decreased to 27/304 (8.9%) when the ITB was 21% to 40% and 60/1034 (5.8%) when the ITB was less than 20% BSA. Burn wound infections developed during 57/211 patient weeks (27.0%) when the initial full-thickness burn (IFB) was greater than 20% BSA. The rate of wound infection decreased to 73/776 (9.4%) when the IFB was 1% to 20% and to 12/536 (2.2%) when no IFB was present. We further analyzed the prevalence of serious wound infections in relation to the open wound size during the hospital course. Wound infections occurred during 47 of 96 patient weeks (49.0%) when the current full-thickness wound was greater than 10% BSA. The infection rate decreased to 76 of 594 (12.8%) and 17 of 833 patient weeks (2.0%) when the remaining full-thickness wound was reduced to 1% to 10% and less than 1% BSA, respectively (p less than 0.05). Early wound closure would appear to reduce the risk of serious wound infections, especially in patients with full-thickness burns.

The importance of burn wound size in determining the optimal calorie:nitrogen ratio.

Calorie requirements in hypermetabolic burned patients have been established based on burn size and patient weight. However, the requirement for nitrogen (N), especially with variable open wound sizes, is not clear. Thirty-six adult burned patients were fed with diets containing two different calorie to N (kcal:N) ratios--150:1 (group 1) and 100:1 (group 2)--and N balance was studied with wounds of different sizes. Calorie requirements were calculated with the Curreri formula (25 cal X weight (kg) + 40 Cal X % body surface area [BSA] burned). Daily N balance was calculated from total N intake less total N output (estimated by adding 4 gm to the measured 24-hour urea N production). The data were selected on 233 patient-days when actual calorie intakes were 100% to 150% of the calculated requirement. For a wound size of 1% to 10% BSA, group 1 patients had an N balance of +2.33 gm/day and group 2, +5.54 gm/day. For a wound size of 11% to 30% BSA, N balance was +0.13 and +3.49 gm/day, respectively. For a wound size of 31% to 60% BSA, N balance was -3.38 and +3.88 gm/day, respectively. The traditional 150:1 kcal:N ratio may be adequate for patients with open wounds of less than 10% BSA. Patients with greater than 10% BSA open wounds require a dietary regimen containing a nonprotein kcal: N ratio of 100:1 in order to achieve positive N balance.

Head injury and hemorrhagic shock: studies of the blood brain barrier and intracranial pressure after resuscitation with normal saline solution, 3% saline solution, and dextran-40.

The effect of fluid resuscitation from hemorrhagic shock on cerebral edema, intracranial pressure (ICP), and blood brain barrier function was investigated in the presence of a simulated head injury. Beagle dogs were anesthetized and ICP was measured via a right subarachnoid bolt while a contralateral epidural balloon was inflated in the left hemicranium to mimic a closed head injury. Forty percent of the dogs' blood was shed and the shock state was maintained for 1 hour. Resuscitation was initiated with shed blood and a volume of either normal saline solution (NS, n = 5), 10% dextran-40 (D-40, n = 6), or hypertonic (3%) saline solution (HS, n = 6) equal to the amount of shed blood. Evans blue solution was infused intravenously, and intravascular volume was then maintained with normal saline solution. Control (n = 5) dogs did not undergo shock, but received equivalent volumes of normal saline solution and Evans blue solution. The dogs were killed after 2 hours of resuscitation, and the brains were removed, weighed, and fixed in formalin. The average intracranial pressure value after epidural balloon inflation was 18.6 +/- 0.80 mm Hg and decreased equally in all groups during the shock period, averaging 10.8 +/- 1.24 mm Hg at the end of the shock period. Fluid resuscitation markedly elevated ICP in the NS and D-40 groups, reaching maximal values of 46.6 +/- 12.11 mm Hg and 45.3 +/- 28.95 mm Hg, respectively. Maximal ICP values in control and HS groups measured 21.8 +/- 1.36 mm Hg and 15.8 +/- 2.04 mm Hg, respectively (p less than 0.25 for HS versus NS control). Wet brain weights were significantly less in the HS group compared with either NS or D-40 groups (p less than 0.05). Coronal sections of fixed HS brains showed deep cortical Evans blue staining on the side of balloon injury. Therefore, in the presence of an intracranial mass lesion, resuscitation with hypertonic (3%) saline solution is accompanied by lower ICP values and less cerebral edema than is isotonic saline or colloid resuscitation. Blood brain barrier function is not restored by hypertonic saline solution resuscitation.

Extracorporeal venovenous recirculation for the treatment of hypothermia during elective aortic surgery: a phase I study.

BACKGROUND: Hypothermia caused by massive transfusion or prolonged exposure during operation is difficult to reverse and is associated with adverse side effects. This prospective, randomized study evaluated a technique using extracorporeal venovenous recirculation (EVR) through a roller pump-driven device with a commercial countercurrent heat exchanger used for treatment of hypothermia (temperature < 35.5 degrees C) occurring during elective aortic operation. METHODS: Patients undergoing aortic operation had routine prophylaxis against hypothermia including ventilator cascades, warming blankets, and low-velocity fluid warmers. When core temperature was less than 35.5 degrees C, patients were randomized to continue existing therapy (control, n = 7) or EVR (n = 8), performed through two large-bore venous lines. RESULTS: There were no differences in age, sex, weight, body surface area, Acute Physiology and Chronic Health Evaluation II score, fluid replacement, length of operation, blood lost or given, induction temperature, red blood cell or platelet structure, hemolysis, length of intensive care unit or hospital stay, complications, or mortality rates. EVR was associated with increased final core temperature (35.5 degrees +/- 0.8 degrees [EVR] vs 33.8 degrees +/- 0.9 degrees [control]; p < 0.005) and body heat content (-13.9 +/- 62.3 kcal [EVR] vs -118.2 +/- 62.2 kcal [control]; p < 0.01), with heat gained being proportional to flow rate. CONCLUSIONS: These data show that EVR provides a safe and effective method for the treatment of hypothermia.

Parathyroid allotransplantation in the treatment of complicated idiopathic primary hypoparathyroidism.

Parathyroid allotransplantation was performed in a 25-year-old woman with idiopathic hypoparathyroidism that had been diagnosed at age 4 years. Long-term medical management of the primary condition with vitamin D and oral calcium supplementation was complicated by multiorgan calcinosis and renal failure. At the age of 21 years she received a successful cadaver renal allograft. Four years later she developed calcinosis cutis with widespread skin necrosis. Medical control of calcium and phosphate metabolism was unsatisfactory and the skin necrosis became progressive and life threatening. A parathyroid allograft that was performed with tissue from a parathyroid adenoma resulted in normalization of the serum calcium and phosphorus levels with arrest and subsequent healing of the skin necrosis. Later failure of the parathyroid allograft was followed by successful retransplantation of normal parathyroid tissue from a cadaver organ donor.

Cardiovascular lymphoscintigraphy.

The technique of lymphoscintigraphy when applied to the heart and blood vessels correlates well with results of anatomic investigations of arterial and cardiac lymphatic vessels reported in the literature. Five dogs and eight rabbits underwent lymphoscintigraphy of the heart and aorta, as well as the iliac, femoral, and tibial arteries. After surgical exposure, approximately 500 microCi of 99mTc-labelled antimony sulfide was injected into the myocardium or the adventitial-medial plane of an artery. The colloid particle size of 4 to 12 m mu causes resorption and transport only via the lymphatic vessels. Twenty-one preparations were imaged from 2 to 48 hours after administration. This method provides a functional demonstration that the tibial and femoral arteries of both species are invested with lymphatics. The first echelon of lymph nodes which drain muscular arteries are imaged within 2 hours. Regional lymph nodes could not be seen to drain the aorta or iliac arteries. Anterior left ventricular myocardial injection in the dog showed a single cardiac lymph node. This drainage pattern has been described previously by other investigators. In the rabbit a similarly placed injection visualized a group of regional cardiac nodes. Ligation of the collecting ducts afferent to the cardiac node in the dog prevented removal of the isotope from the heart at 3, 6, and 9 hours. At 24 hours the liver and spleen were imaged, the radiocolloid gaining entrance to the blood vascular system presumably via myocardial lymphaticovenous anastomoses. Lymphoscintigraphy reflects physiologic processes such as lymph transport, filtration, and reticuloendothelial function. It defines regional patterns of cardiac and arterial lymph drainage. It can confirm experimentally produced impairment of lymph drainage from a defined area of tissue. Lymphoscintigraphy should be useful in the investigation of the significance of lymph drainage to diseases of the heart and blood vessels.

Partial splenic embolization, an alternative to splenectomy--results of a prospective, randomized study.

UNLABELLED: We conducted a prospective, randomized study comparing transcatheter partial splenic embolization (PSE) with splenectomy (SX) in 53 renal transplant candidates. An additional 112 PSE procedures were performed for various indications in 101 patients. STUDY RESULTS: A mean +/- SD of 65% +/- 16% of splenic mass was ablated in the PSE group. The early postoperative morbidity rate was similar in the two study groups, as was the duration of hospital stay. Abscess or rupture of the spleen were not encountered. Severe pancreatitis occurred only in the SX group. Renal transplantation was carried out in equivalent numbers in both groups, with a similar long-term (2.5 to 4.0 years) graft survival (60% versus 66%). No difference in long-term patient mortality was noted. Splenic "regeneration" occurred frequently after PSE. PSE experience exclusive of study: Embolization attempts failed in nine patients. Repeat PSE was performed in 11 of the 101 patients. Where hypersplenism was the primary indication, PSE resulted in significant improvement in the hematologic parameters. The incidence of serious complications was acceptably low. There were two late procedure-related deaths. Our conclusion from the study and the total experience of 137 PSE procedures is that PSE offers an acceptably safe alternative to SX in selected high-risk patients in whom both the surgical intervention and the resulting asplenic state carry a prohibitive risk.

Biochemical changes in rhesus monkey during the first days after streptozotocin administration are indicative of selective beta cell destruction.

Hormonal and glycemic changes in 22 rhesus monkeys were characterized during the first days after treatment with streptozotocin (STZ) (45 to 55 mg/kg, administered intravenously [IV]). Almost half (10/22) of the monkeys developed insulin-dependent diabetes mellitus (STZ-IDDM) within five days following injection. Four of the remaining monkeys did not become insulin dependent for at least 6 months after STZ treatment, during which time they were considered non-insulin-dependent, and eight monkeys never required exogenous insulin. In the STZ-IDDM group, plasma immunoreactive c-peptide (IRC-P) levels fell by three hours after STZ from a mean +/- SEM of 252 +/- 82 to 101 +/- 45 pg/mL, as glucose and immunoreactive glucagon (IRG) levels increased from 65 +/- 3 and 120 +/- 37, respectively, to 336 +/- 43 mg/dL and 234 +/- 52 pg/mL, respectively. Between six and 30 hours after treatment, IRC-P increased to a peak of 1,561 +/- 360 pg/mL before falling permanently to less than 60 pg/mL by 66 hours. During this period, glucose and IRG responded in a reciprocal fashion by falling and then increasing to levels above 300 mg/dL and 300 pg/mL, respectively, by 66 hours. In the non-insulin-dependent diabetes mellitus (STZ-NIDDM) group, no clear reciprocal relationship between IRC-P and glucose and IRG was obtained. In nine additional monkeys subjected to total pancreatectomy (Px), IRC-P and IRG levels fell immediately and permanently by greater than 90% and 75%, respectively. Levels of immunoreactive somatostatin increased steadily over the initial 96 hours following STZ, but did so both STZ-IDDM and Px monkey groups.(ABSTRACT TRUNCATED AT 250 WORDS)

Women as leaders in organized surgery and surgical education. Has the time come?

Women have entered medicine in large numbers during the past three decades, and are increasing their representation in some surgical fields at a rapid pace. Few women are found in senior roles in organized surgery or at the senior ranks of academic surgical faculty. Factors influencing this imbalance include family demands, sexism, and stereotypes that hinder the advancement of women into leadership roles. Strategies for correcting this imbalance include affirmative recruitment of women into surgery, particularly into academic surgical faculties; support systems, such as child care and adjustment of promotion and tenure timetables; mentoring; and programs of career development that emphasize skills in management as well as research and teaching.

Hepatic dysfunction during isoniazid chemoprophylaxis in renal allograft recipients.

Hepatitis is a frequent complication of dialysis and renal transplantation; therefore, the occurrence of drug hepatotoxicity is an additional important consideration in renal allograft recipients. Azathioprine, needed for immunosuppression, and isoniazid, used for antituberculous chemoprophylaxis, are both potentially hepatotoxic. A retrospective study of 119 patients who received 126 renal allografts was done to estimate the probable incidence of isoniazid-related hepatic dysfunction. All patients in this series were administered isoniazid chemoprophylaxis. Posttransplantation hepatitis developed in 13 patients. Circumstantial evidence supported a presumptive diagnosis of isoniazid hepatotoxicity in three recipients. We concluded that routine isoniazid chemoprophylaxis is not justified in renal allograft recipients based on the probability of hepatotoxicity as contrasted to the infrequent occurrence of tuberculosis.

Total parathyroidectomy and autotransplantation in secondary hyperparathyroidism.

Sixteen patients with chronic renal failure and symptomatic secondary hyperparathyroidism underwent total parathyroidectomy. Sixteen to 25 fragments of parathyroid tissue measuring 1 cu mm were autotransplanted into the brachioradial muscle. Evidence of "take" of the autotransplant was present in all patients, although four patients still have hypocalcemia and require calcium and vitamin D supplementation. Three patients have experienced late diminution of autotransplant function. Symptomatic improvement occurred promptly in 15 of the 16 patients. Two patients with persistently elevated parathormone levels were treated by partial excision of the implant, and one patient whose autograft functioned inadequately was successfully treated by implantation of cryopreserved autologous parathyroid tissue. Total parathyroidectomy with autotransplantation of parathyroid fragments to the forearm is the preferred surgical procedure for secondary hyperparathyroidism.

Amebic liver abscess.

Amebic liver abscess was seen in 35 patients over a ten-year period at Cook County and the University of Illinois hospitals, Chicago; 32 had immigrated from an area of endemic amebiasis, but three were natives of Chicago. Typically they had right upper-quadrant abdominal pain and fever of short duration (nine days); on physical examination, upper abdominal tenderness and hepatomegaly were usually present. The diagnosis was confirmed by liver scan, serologic studies, aspiration of "anchovy paste" from the abscess, and/or a favorable response to specific antiamebic therapy. Most were solitary abscesses in the right lobe of the liver. Metronidazole treatment alone was adequate in 24 of 29 patients (83%). Nine patients underwent percutaneous or surgical drainage of the abscess owing to incorrect diagnosis (three), persistent pain and fever after medical treatment (three), expanding left lobe abscess (two), and for diagnosis (one). Mortality was 5.7% (two patients). Owing to current immigration patterns amebic liver abscess should be considered in the differential diagnosis of patients with right upper-quadrant pain and fever. The diagnosis should be confirmed with a liver scan and serologic study for amebiasis.

Treatment of extensive renal calculi with extracorporeal surgery and autotransplantation.

Two patients with large calculi in solitary kidneys, treated by ex vivo stone extraction and autotransplantation, are presented. The results show this to be a valuable therapeutic modality for difficult renal calculi where an in situ approach would be hazardous.

The longitudinal study of surgical residents, 1993 to 1994.

BACKGROUND: The American College of Surgeons (ACS) has collected comprehensive data about surgical residents for the past 12 years and has published an annual report, the Longitudinal Study of Surgical Residents. In 1994, the ACS and the American Medical Association (AMA) agreed to collaborate in collecting data about surgical residents. We report the analysis of these data for residents enrolled in graduate medical education (GME) in surgery during the 1993 to 1994 academic year. STUDY DESIGN: Data about residents and fellows during the 1993 to 1994 academic year, including the 1994 graduates from 13 surgical specialties, were obtained from the AMA. Through additional mailings and telephone contact by the ACS, data were obtained and verified from each of the 1,500 accredited surgical residency programs. The resulting data set was analyzed to derive a count of residents and fellows and graduates for the 1993 to 1994 academic year. The ACS Resident Masterfile was analyzed separately to compare the 1993 to 1994 results with those from previous years. RESULTS: The total number of surgical residents enrolled in GME has changed little since 1982. Since 1987, the number of graduates has increased 2.1 percent. More general surgery graduates are enrolling in advanced specialty GME than were enrolling in 1982. The average age of graduates from core residency programs is 33 years, of advanced program graduates is 35 years, and of international medical graduates is 36 years. International medical graduates represent 7.1 percent of all surgical residents and fellows and 5.5 percent of graduates. Women and ethnic minorities are underrepresented in surgical GME. CONCLUSIONS: Surgical GME enrollment has been stable since 1982, and graduates of general surgery residencies are increasingly likely to enroll in advanced specialty residency programs.

The longitudinal study of surgical residents, 1994 to 1996.

BACKGROUND: The American College of Surgeons (ACS) has conducted a detailed annual survey of residents enrolled in surgical graduate medical education (GME) programs since 1982 and has regularly published the resulting data as the Longitudinal Study of Surgical Residents. This report documents surgical resident enrollment and graduation for the academic years 1994-95 and 1995-96. STUDY DESIGN: The Medical Education Research and Information Database of the American Medical Association was supplemented by the existing ACS Resident Masterfile and by personal contact with program directors and their staffs to verify accuracy and completeness of reporting. Each resident was tracked individually through surgical GME. RESULTS: The total number of surgical residents graduating from surgical GME in 1995 and 1996 has not changed since 1982. Most graduates of surgical residency programs are in obstetrics and gynecology, followed by general surgery; demographic analysis of the graduating cohort shows that most are Caucasian male graduates of US or Canadian medical schools, and that their age at graduation is 33 to 35 years. International medical graduates (IMG) make up 8.9% of entering surgical residents and 6% of graduates. Osteopathic medical school graduates account for 1.2% to 1.3% of entering and graduating surgical residents. Women represent 27% of entering and 23% to 24% of graduates of surgical GME. The largest number and proportion of women in surgical GME are enrolled in obstetrics and gynecology residency programs, where they make up the majority of entering and graduating classes. When all other surgical residency program enrollments are considered together, women make up 17% and 16% of entering residents in 1994 and 1995, respectively, and 13% and 14% of graduates in those years. CONCLUSIONS: Surgical GME enrollment and graduation is stable. Few women and ethnic minorities are enrolled in surgical residency programs. IMG enrollment and graduation in surgical GME is low.