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D L Dunn

Publications and source records attributed to D L Dunn.

At least 19 recordsLinked to original sources
PubMed1996

Pregnancy after donor nephrectomy.

Potential female donors frequently ask whether unilateral nephrectomy will impair future childbearing capabilities. To address this question, we surveyed 220 women who underwent donor nephrectomy between 1985 and 1992. Of the 144 women who responded, 33 became pregnant after donation for a total of 45 pregnancies. Seventy-five percent of the pregnancies were carried to term without difficulty. Complications incurred during gestation included miscarriage (13.3%), preeclampsia (4.4%), gestational hypertension (4.4%), proteinuria (4.4%), and tubal pregnancy (2.2%). Four of the 45 pregnancies (excluding miscarriages) required preterm hospitalization, resulting in an overall morbidity of 8.8%. There were no pregnancy-related deaths, and no fetal abnormalities were reported. Problems with persistent hypertension, proteinuria, or changes in renal function were not noted. None of the above complications exceeded what has been noted for the general population. Infertility was a problem in 8.3% (3/36) of our respondents, compared with a worldwide incidence of 16.7%. Based on these results, we conclude that donor nephrectomy is not detrimental to the prenatal course or outcome of future pregnancies.

Female↗
PubMed1996

Renal transplantation exposes patients with previous Kaposi's sarcoma to a high risk of recurrence.

It is currently estimated that about 0.5% of patients will develop Kaposi's sarcoma (KS) after kidney transplantation. Tapering of immunosuppression often leads to KS remission, but also results in graft loss in more than 50% of cases. Whether retransplantation is safe in these patients is unknown. We here report on eight patients who developed KS recurrence after kidney transplantation-(A) Patients with previously treated KS: There were 4 patients who had clinical remission of KS (including three posttransplantation) for periods ranging from 5 months up to 19 years before transplantation. All 4 developed KS recurrence within months after transplantation. In 3 patients, KS regressed only when all immunosuppression was discontinued, at the price of allograft removal. Partial remission occurred in the fourth patient following reduction of immunosuppression and gancyclovir administration; (B) Patients with recurrent KS during a single transplant: 4 patients developed KS after transplantation that regressed following reduction of immunosuppressive therapy. Increased immunosuppression, in the form of steroid pulses in 3 patients was associated with recurrence of KS. Subsequent reduction of immunosuppression caused regression of KS in all 4 patients, but 2 recipients lost their allografts. These data emphasize the high risk of recurrence of KS after renal transplantation. If physicians decide to transplant patients with a history of KS, they should inform the future recipient of the possibility of KS recurrence.

Adult↗
PubMed1996

Delayed graft function in the absence of rejection has no long-term impact. A study of cadaver kidney recipients with good graft function at 1 year after transplantation.

We previously reported that delayed graft function (DGF) in the absence of biopsy-proven acute rejection (Rej) had no effect on outcome of primary cadaver kidney transplantation (TX). By contrast, DGF in combination with Rej strongly predicted poor long-term graft survival. We asked whether this poor long-term outcome was due to early graft loss associated with DGF, or to an ongoing process leading to late graft loss. To answer this question, we studied a subset of 298 cadaver kidney transplant recipients who had not suffered early graft loss and had a serum creatinine level < or = 2.0 mg/dl at 1 year after TX. The incidence of DGF (defined by dialysis during the first week after TX) in this subset was 19%. DGF was associated with cold ischemia time >24 hr (P = 0.0003) and Rej (P = 0.06). For grafts with versus without DGF, the incidence of late acute Rej (>1 year after TX) was similar. Actuarial graft survival was similar for Rej-free recipients with versus without DGF (P = 0.9) and was worse for those with Rej and no DGF (P < 0.02). Importantly, however, in our recipients who all had a serum creatinine level < or = 2.0 mg/dl at 1 year after TX, the worst long-term outcome was noted in the subgroup with both DGF and Rej (P < 0.0001). By multivariate analysis, DGF was also only a risk factor in combination with Rej (P = 0.002, relative risk = 3.7), while a 0-antigen HLA mismatch had no impact. Patient survival decreased for recipients with both DGF and Rej by univariate (P = 0.009) and multivariate (P = 0.02, relative risk = 2.9) analyses. We conclude that DGF without Rej has no impact on long-term survival. However, our data for recipients with both DGF and Rej suggest that a chronic ongoing process leads to late graft failure. Further research is necessary to identify the exact pathophysiology of this process, which appears to be, at least in part, HLA antigen independent.

Acute Disease↗
PubMed1996

Employment patterns after successful kidney transplantation.

We studied 822 kidney transplant recipients followed 1-9 years to determine the dynamics of their entering and leaving the work force. Multivariate analysis revealed that not being diabetic and that being employed pretransplant were associated with a higher rate of posttransplant employment. Some recipients in all pretransplant employment categories, including those receiving disability benefits pretransplant, returned to full-time work posttransplant. The most rapid return to work was in those who had been working full-time or attending school pretransplant. After returning to work, a higher percentage of diabetic recipients stopped working; of those who stopped working, 50% received disability benefits. In contrast, nondiabetic recipients who stopped working full-time were more likely to be retired or working part-time; only 22% received disability benefits.

Adult↗
PubMed1996

Bacterial translocation in a large-animal model of small-bowel transplantation. Portal vs systemic venous drainage and the effect of tacrolimus immunosuppression.

OBJECTIVE: To study whether bacterial translocation is more prevalent after small-bowel transplantation with systemic venous drainage (SVD) vs portal venous drainage (PVD) and whether it is influenced by immunosuppression. DESIGN: We performed 15 small-bowel transplantations in pigs. Group 1 (n = 5) had SVD and no immunosuppression; group 2 (n = 6), PVD and no immunosuppression; and group 3 (n = 4), PVD and immunosuppression with tacrolimus and methylprednisolone sodium succinate. Portal and systemic blood, portal and mesenteric lymph nodes, and liver were cultured in donors and recipients on postoperative day 0 (POD 0) and in recipients on postoperative day 3 (POD 3). Jejunal and ileal contents were also sampled at these times. SUBJECTS: Outbred male Yorkshire-Landrace pigs. MAIN OUTCOME MEASURES: (1) Blood and tissue bacterial cultures, (2) blood endotoxin levels, and (3) histopathologic examination. RESULTS: Cultures were positive for bacteria in 32% (16/50) of samples on POD 0 and 88% (22/25) on POD 3 in group 1, in 18% (11/60) of samples on POD 0 and 97% (29/30) on POD 3 in group 2, and in 8% (3/40) of samples on POD 0 and 95% (19/20) on POD 3 in group 3. Systemic blood cultures were positive for bacteria on POD 3 in 60% (3/5) of pigs in group 1, 83% (5/6) in group 2, and 100% (4/4) in group 3. Significantly more bacteria were present in the ileum than in the jejunum on POD 0 in group 2; this difference approached significance in groups 1 and 3. Bacterial numbers were identical in the ileum and jejunum by POD 3 in all groups. Circulating endotoxin levels were significantly elevated on POD 3 vs POD 0 only in group 1. Endotoxin levels were not significantly different between the SVD group (group 1) and either PVD group (groups 2 and 3). CONCLUSIONS: Bacterial translocation is prevalent after small-bowel transplantation in pigs whether PVD or SVD is used. Immunosuppression with tacrolimus does not prevent bacterial translocation but may reduce systemic endotoxemia.

Animals↗
PubMed1996

Pancreas graft loss caused by intra-abdominal infection. A risk factor for a subsequent pancreas retransplantation.

OBJECTIVE: To investigate whether previous pancreas graft loss caused by intra-abdominal infection is a risk factor for a subsequent pancreas retransplantation. DESIGN: Retrospective case-series analysis. SETTING: Large university hospital. PATIENTS: Of 97 pancreatic retransplantations (July 1, 1985 to June 30, 1994), 13 (13%) were performed after previous pancreas grafts had been lost because of intra-abdominal infection. MAIN OUTCOME MEASURES: Cause of retransplant graft loss; patient survival. RESULTS: Of 13 cases of pancreatic retransplantations performed after previous grafts had been lost because of intra-abdominal infection, 12 (92%) were again complicated by intra-abdominal infection. Of these 12 retransplantation infections, 10 were caused by the same microbial species that had caused failure of the previous graft 1 to 5 years earlier (8 required graft pancreatectomy [mortality rate, 25%], and 2 were successfully treated) and 2 were caused by different microbial species (both required graft pancreatectomy [mortality rate, 0%]). In 1 of the 13 retransplantations, prophylactic antimicrobial treatment was directed at the microbial species that had caused failure of the previous graft; no recurrent intra-abdominal infection developed. CONCLUSIONS: Intra-abdominal infection after a previous pancreas transplantation is a risk factor for recurrence of infection by the same microbial species after a subsequent retransplantation. For the selected patients who are considered for retransplantation in spite of their previous graft loss caused by intra-abdominal infection, periretransplantation antimicrobial prophylaxis should include a prolonged course of an agent directed against the previously identified microbial species.

Abdomen↗
PubMed1996

Macrophages expressing a fusion protein derived from bactericidal/permeability-increasing protein and IgG are resistant to endotoxin.

OBJECTIVES: To generate a recombinant fusion protein (FP) based on the endotoxin-binding domain of bactericidal/permeability-increasing protein (BPI) and the constant domain of IgG and to test its ability to inhibit lipopolysaccharide (LPS)-induced macrophage tumor necrosis factor alpha (TNF-alpha) secretion. DESIGN: A murine macrophage cell line, RAW 264.7, was transfected with a BPI-IgG FP before incubation with LPS. The amount of LPS-induced TNF-alpha protein secreted was measured and compared with that secreted by cells transfected with a control construct. SETTING: Basic science research laboratory. MAIN OUTCOME MEASURES: Secreted TNF-alpha protein concentration. RESULTS: After transfection, RAW 264.7-cell FP expression was detected in cell lysates and supernatants. At each LPS dose tested, cells transfected with the FP gene secreted less TNF-alpha than did cells transfected with a control construct. CONCLUSIONS: The FP possesses substantial antiendotoxin activity, as delineated by inhibition of LPS-induced TNF-alpha secretion by murine macrophages transfected with the fusion gene construct. In the future, such FP may be used as a clinical reagent to reduce the morbidity and mortality associated with serious gram-negative bacterial infections in surgical patients.

Animals↗
PubMed1996

Differential sensitivity to Escherichia coli infection in mice lacking tumor necrosis factor p55 or interleukin-1 p80 receptors.

OBJECTIVE: To determine the effect of targeted disruption of the cellular receptors of either tumor necrosis factor alpha (TNF-alpha) or interleukin-1 beta (IL-1 beta) during experimental gram-negative bacterial infection and endotoxemia. DESIGN: Transgenic (knockout [KO]) mice deficient in either the p55 TNF receptor (TNF RI) or the p80 IL-1 receptor (IL-1 RI) were challenged with intravenous lipopolysaccharide (endotoxin) or intraperitoneal live Escherichia coli 0111:B4. Mortality was assessed daily for 7 days. Serum endotoxin levels and quantitative blood cultures were monitored at multiple times during infection. SETTING: Surgical infectious disease research laboratory. MAIN OUTCOME MEASURES: Mortality, results of quantitative blood cultures, and serum endotoxin levels. RESULTS: Both TNF and IL-1 RI KO mice were resistant to endotoxin challenge (0% mortality for both groups) compared with control mice (100% mortality [P < .01]). In contrast, only the IL-1 RI KO mice were resistant to infection caused by viable gram-negative bacteria (43% mortality) compared with control mice (100% mortality [P < .01]). Infection led to 100% mortality in TNF RI KO mice. The IL-1 RI KO mice exhibited less bacteremia and diminished endotoxemia compared with control and TNF RI KO mice 18 and 24 hours after infection. CONCLUSION: The absence of either the TNF or the IL-1 RI receptor prevents cellular activation by each respective cytokine. Absence confers protection against intravenous endotoxin, which stimulates massive rapid release of cytokines into the systemic circulation. However, bacterial infection within the peritoneal cavity is known to cause more delayed cytokine release, and cytokines may act at the site of infection to enhance host defenses. We believe that IL-1 signaling may be more critical in provoking lethal systemic toxic effects than TNF signaling. However, TNF signaling may be an important component of host defense enhancement at the local site of infection.

Animals↗
PubMed1996

Projections.

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Animals↗
PubMed1996

A novel endotoxin antagonist attenuates tumor necrosis factor-alpha secretion.

Twenty-seven amino acid peptides with sequences corresponding to a proposed endotoxin binding region of bactericidal permeability increasing protein (BPI):1) inhibit lipopolysaccharide induced macrophage tumor necrosis factor-alpha (TNF-alpha) secretion, 2) have bactericidal activity against gram-negative bacteria, and 3) protect mice from a lethal lipopolysaccharide (LPS) challenge. Unfortunately, peptides have a short halflife in vivo. Therefore, we have chemically conjugated the BPI based peptide, BG38, to a larger carrier protein, keyhole limpet hemocyanin (KLH), and characterized its ability: 1) to inhibit LPS induced macrophage TNF-alpha secretion and 2) to decrease plasma endotoxin and TNF-alpha levels following an i.v. injection of E. coli 0111:B4 LPS. BG38-KLH inhibited cultured macrophage TNF-alpha secretion in response to LPS derived from four pathogenic strains of gram-negative bacteria in a dose dependent manner (>90% inhibition at 50 microgram/ml, P < 0.05 Student's t test). BG38-KLH also decreased serum endotoxin (>90%, P < 0.05 Student's t test) and peak TNF-alpha levels (>30% inhibition, P < 0.05 Student's t test) following E. coli LPS challenge in a murine gram-negative bacterial sepsis model. Novel endotoxin antagonists based upon a small domain of BPI represent promising reagents for the treatment of serious gram-negative bacterial infections.

Animals↗
PubMed1996

Mycoplasma hominis infections occurring in cardiovascular surgical patients.

BACKGROUND: Postoperative Mycoplasma hominis sternal would or mediastinal infections are uncommon and difficult to diagnose. Atypical growth characteristics in routine bacterial culture, and the inability to demonstrate the organism on Gram stain, lead to delayed diagnosis of M hominis infections and increased morbidity. METHODS: Postoperative purulent would drainage or acute mediastinitis caused by M hominis developed in 3 cardiovascular surgery patients. These patients were considered along with 9 patients previously reported in the literature. RESULTS: Operative findings included moderately thick, gray purulent fluid with the degree of tissue necrosis related to duration of infection. Intraoperative Gram stain of wound or mediastinal drainage demonstrated no microorganisms, and initial bacterial cultures did not reveal microbial growth. After an average of 4.5 days of culture, minute translucent colonies of M hominis were identified. The institution of appropriate antimycoplasma therapy (doxycycline and clindamycin) was associated with clinical or microbiological cure in all patients. Sternal wound complications developed in 3 patients, and a chronic infection developed in 1 patient. CONCLUSIONS: Empiric therapy for M hominis infection should be considered in patients with mediastinitis or a sternal wound infection in which organisms are not observed on Gram stain and are not readily cultured.

Acute Disease↗
PubMed1996

Diagnosis and treatment of bacteremia and intravascular catheter infections.

The past decade has witnessed an explosive rise in the rate of bacteremia and intravascular catheter infection. Although gram-negative organisms continue to account for up to one third of these infections, gram-positive organisms have become increasingly prevalent pathogens. Virulent antibiotic-resistant bacterial strains have emerged and present a formidable treatment challenge. Simultaneously, management of catheter infection has evolved. Although patients who develop fungemia, gram-negative bacteremia, or sepsis syndrome are best treated by catheter removal in addition to antimicrobial therapy, an increasing body of evidence suggests that many gram-positive bacterial catheter infections can be treated by use of antimicrobial agents without catheter removal. Advances in catheter design and immunotherapy for sepsis syndrome also hold promise. Despite these innovations, determining the initial need for catheter placement, adherence to meticulous sterile surgical technique during insertion, and subsequent fastidious catheter maintenance remain the mainstays of preventing these potentially disastrous infections.

Anti-Bacterial Agents↗
PubMed1996

Vascular graft thrombosis after pancreatic transplantation: univariate and multivariate operative and nonoperative risk factor analysis.

BACKGROUND: Vascular thrombosis is still the leading cause of nonimmunologic, technical pancreatic transplant graft failures. The paucity of published data--coupled with our large institutional experience with pancreatic transplantation in all recipient and transplant categories, using a wide spectrum of surgical techniques--provided the impetus for a retrospective study of graft thrombosis risk factors. STUDY DESIGN: Four hundred thirty-eight patients with pancreatic transplants (45 percent simultaneous pancreas-kidney [SPK], 23 percent pancreas-after-kidney [PAK], and 32 percent pancreatic transplants alone [PTA] and with Type I insulin-dependent diabetes mellitus were studied retrospectively. Of 438 pancreatic transplants, 90 percent were bladder-drained and 10 percent were enteric-drained. Ninety-three percent were from cadaver donors, 90 percent were whole-organ grafts, and 20 percent were retransplantations. Quadruple immunosuppression was given. For bladder-drained, whole-organ transplantations (n=378), we performed Cox regression analyses to study the impact on pancreatic graft thrombosis of donor, recipient, mode of preservation, and surgical variables. RESULTS: The overall thrombosis rate was 12 percent (5 percent arterial, 7 percent venous). For cadaver, bladder-drained, whole-organ pancreatic transplants, the thrombosis incidence was highest in PAK recipients (20 percent). The PAK category was also found to be an independent risk factor for thrombosis by stepwise Cox regression analysis. In separate stepwise Cox regression analyses for each category, other identified risk factors for thrombosis included the following: donor age (PAK, PTA); cardiocerebrovascular cause of donor death (SPK, PAK); the use of an aortic Carrel patch (SPK); arterial pancreatic graft reconstruction using a splenic artery to superior mesenteric artery anastomosis (SPK, PTA) or an interposition graft between the splenic artery and the superior mesenteric artery (PTA); portal vein extension graft (PAK); left-sided implantation into the recipient (PAK); and graft pancreatitis (defined as hyperamylasemia exceeding five days post-transplant [PAK, PTA]). CONCLUSIONS: Older donors or those who died of cardiocerebrovascular disease should not be considered for any recipient category. Preservation time needs to be minimized and strategies need to be developed to decrease graft pancreatitis. Surgically, left-sided implantation and arterial reconstructions other than the Y-graft also increase risk, as do portal vein extensions. Renal transplants alone in prospective PAK recipients with Type I diabetes mellitus should, therefore, always be implanted left-sided to allow for right-sided pancreatic graft placement.

Adult↗
PubMed1996

Intra-abdominal fungal infections after pancreatic transplantation: incidence, treatment, and outcome.

BACKGROUND: Intra-abdominal infections account for 15 percent of technical failures after pancreatic transplantation. Although some data are available about intra-abdominal bacterial infections, no study has analyzed the incidence, treatment, and outcome of intra-abdominal fungal infections. STUDY DESIGN: We retrospectively studied 445 consecutive pancreatic transplantations--45 percent were simultaneous pancreatic and renal, 24 percent pancreatic after renal, and 31 percent pancreatic transplantations alone--in patients with Type I diabetes mellitus. Donors were cadavers in 92 percent and living relatives in 8 percent. Primary transplantations were done in 80 percent and retransplantation in 20 percent. Of these 445 pancreatic transplantations, 90 percent were bladder-drained, 9 percent enteric-drained, and 1 percent duct-injected. Only symptomatic patients with documented culture-positive intra-abdominal fungal infections were included. RESULTS: Intra-abdominal fungal infections occurred after pancreatic transplantation in 41 (9.2 percent) of 445 patients. Donor age, but not recipient age, was a significant risk factor. The rate of infections was higher for enteric-drained (21 percent) than for bladder-drained (10 percent) transplantations; for organs donated by living relatives (16 percent) than for those from cadavers (9 percent); and for pancreatic after renal (12 percent) and simultaneous pancreatic-renal (11 percent) than for pancreatic-only (5 percent) recipients. The rate of intra-abdominal fungal infections was 6 percent for recipients who were given antifungal prophylaxis (fluconazole, 400 mg/day for seven days after transplantation) compared with 10 percent for those without prophylaxis. The one-year graft survival rate for recipients with infection was 17 percent compared with 65 percent for those without (p = 0.0001); the survival rate was 70 percent compared with 92 percent for patients with and without infection, respectively (p = 0.0007). In 22 percent of recipients, the infection resolved and graft function persisted; in 58 percent, the infection resolved after transplant pancreatectomy; and in 20 percent, death occurred despite transplant pancreatectomy. Recipients with sole fungal or fungal and bacterial infection (n = 41) were 50 percent less likely to recover with a functioning graft and had a risk of death that was three times higher (p < or = 0.05) than those with sole bacterial infection (n = 48). CONCLUSIONS: Intra-abdominal fungal infections after pancreatic transplants are associated with high morbidity and mortality rates, significantly higher than for sole bacterial infections. In addition to aggressive treatment, including transplant pancreatectomy and reduction of immunosuppression, efforts must be made toward better prevention of intra-abdominal fungal infections.

Adult↗
PubMed1996

A third kidney transplant: cost-effective treatment for end-stage renal disease?

Given the organ donor shortage, some question whether a third kidney transplant can be justified. We studied the outcome of 51 third transplants (mean age 28 +/- 2 yr) done between 1 January 1985 and 31 December 1994. We compared hospital stay (mean +/- S.E.), cost, readmissions, readmission days, and outcome of third (vs. first and second) transplants. We found that patient survival for third transplants was equivalent to first and second transplants; graft survival was not as good. However, when third transplant recipients with recurrent disease (specifically, hemolytic uremic syndrome and focal sclerosis) were excluded from our analysis, we found no difference in 5-yr graft survival (vs. first or second transplant recipients). Of the 51 third transplant recipients, 41 had a cadaver donor transplant. Third cadaver transplant recipients tended to have a longer hospital stay (p = NS) than first cadaver transplant recipients but had no more readmissions or readmission days than first and second cadaver transplant recipients. Employment data are available for 28 third transplant recipients; 16 (57%) are currently working or going to school. Of the 21 recipients who responded to quality of life questionnaires, 17 (81%) reported being healthy and all 21 (100%) said transplantation was not a drawback to their health. We conclude that third transplants should be considered for selected patients with renal failure whose first and second transplants have failed. Such patients can often be successfully transplanted.

Actuarial Analysis↗
PubMed1995

A prospective study of FK506 versus CsA and pig ATG in a porcine model of small bowel transplantation.

Rejection remains a major barrier to successful bowel transplantation, and immunosuppressive protocols are far from standardized. In 88 nonrelated outbred pigs, we compared the effects of two immunosuppressive regimens--one with FK506, the other with cyclosporine (CsA) and pig antithymocyte globulin (ATG)--on incidence and severity of rejection in the early, critical posttransplant period. Group A (n = 14) was nonimmunosuppressed (controls). Group B (n = 17) received pig ATG (10 mg/kg/day x 10 days), CsA (3 mg/kg/day), prednisolone (2 mg/kg/day), and azathioprine (2.5 mg/kg/day); prednisolone and azathioprine were each reduced by 50% at 8 and 15 days posttransplant. Trough CsA whole-blood concentrations were > or = 400 ng/ml for the first 7 days, > or = 200 ng/ml thereafter. Group C (n = 13) received FK506 (0.2 mg/kg/day) and prednisolone (2 mg/kg/day); prednisolone was reduced by 50% at 8 and 15 days. FK506 whole-blood concentrations were > or = 20 ng/ml. All immunosuppression in groups B and C was given intravenously. We performed orthotopic small bowel transplants with systemic venous drainage. Recipient bowel was resected distal to the second portion of the duodenum and proximal to the rectum at transplant; bowel continuity was restored by duodenojejunostomy; ileostomy was created distally to allow access for daily biopsies. We graded interstitial and vascular rejection separately, according to a scoring system (no, mild, moderate, and severe rejection). Rejection-free graft survivals at 7, 14, and 21 days posttransplant were 38%, 19%, and 0% in group A; 93%, 93%, and 62% in group B; and 100%, 91%, and 82% in group C (P < 0.001). Comparing rejection in the immunosuppressed groups, group C (FK506) had a stronger tendency toward rejection than group B (CsA-ATG); significant differences between groups B and C were, however, noted only on individual days posttransplant, not over time. The death rate due to irreversible rejection was not significantly different in groups B and C (P = 0.8), but was significantly better in both of these immunosuppressed groups than in group A (P < 0.001). Pig survival was significantly longer in group C than in B (P = 0.001) due to a lower infection rate in group C. Posttransplant serum interleukin 2 and 7 levels did not correlate with rejection grades. Graft-versus-host reaction was noted only in the skin in 29% of group A, 73% of group B, and 77% of group C pigs; liver and native bowel were not involved.(ABSTRACT TRUNCATED AT 400 WORDS)

Animals↗