Improvements in survival and clinical benefit with gemcitabine as first-line therapy for patients with advanced pancreas cancer: a randomized trial

PURPOSE

Most patients with advanced pancreas cancer experience pain and must limit their daily activities because of tumor-related symptoms. To date, no treatment has had a significant impact on the disease. In early studies with gemcitabine, patients with pancreas cancer experienced an improvement in disease-related symptoms. Based on those findings, a definitive trial was performed to assess the effectiveness of gemcitabine in patients with newly diagnosed advanced pancreas cancer.

PATIENTS AND METHODS

One hundred twenty-six patients with advanced symptomatic pancreas cancer completed a lead-in period to characterize and stabilize pain and were randomized to receive either gemcitabine 1,000 mg/m2 weekly x 7 followed by 1 week of rest, then weekly x 3 every 4 weeks thereafter (63 patients), or to fluorouracil (5-FU) 600 mg/m2 once weekly (63 patients). The primary efficacy measure was clinical benefit response, which was a composite of measurements of pain (analgesic consumption and pain intensity), Karnofsky performance status, and weight. Clinical benefit required a sustained (> or = 4 weeks) improvement in at least one parameter without worsening in any others. Other measures of efficacy included response rate, time to progressive disease, and survival.

RESULTS

Clinical benefit response was experienced by 23.8% of gemcitabine-treated patients compared with 4.8% of 5-FU-treated patients (P = .0022). The median survival durations were 5.65 and 4.41 months for gemcitabine-treated and 5-FU-treated patients, respectively (P = .0025). The survival rate at 12 months was 18% for gemcitabine patients and 2% for 5-FU patients. Treatment was well tolerated.

CONCLUSION

This study demonstrates that gemcitabine is more effective than 5-FU in alleviation of some disease-related symptoms in patients with advanced, symptomatic pancreas cancer. Gemcitabine also confers a modest survival advantage over treatment with 5-FU.

Tumor vascular permeability factor stimulates endothelial cell growth and angiogenesis

Vascular permeability factor (VPF) is an Mr 40-kD protein that has been purified from the conditioned medium of guinea pig line 10 tumor cells grown in vitro, and increases fluid permeability from blood vessels when injected intradermally. Addition of VPF to cultures of vascular endothelial cells in vitro unexpectedly stimulated cellular proliferation. VPF promoted the growth of new blood vessels when administered into healing rabbit bone grafts or rat corneas. The identity of the growth factor activity with VPF was established in four ways: (a) the molecular weight of the activity in preparative SDS-PAGE was the same as VPF (Mr approximately 40 kD); (b) multiple isoforms (pI greater than or equal to 8) for both VPF and the growth-promoting activity were observed; (c) a single, unique NH2-terminal amino acid sequence was obtained; (d) both growth factor and permeability-enhancing activities were immunoadsorbed using antipeptide IgG that recognized the amino terminus of VPF. Furthermore, 125I-VPF was shown to bind specifically and with high affinity to endothelial cells in vitro and could be chemically cross-linked to a high-molecular weight cell surface receptor, thus demonstrating a mechanism whereby VPF can interact directly with endothelial cells. Unlike other endothelial cell growth factors, VPF did not stimulate [3H]thymidine incorporation or promote growth of other cell types including mouse 3T3 fibroblasts or bovine smooth muscle cells. VPF, therefore, appears to be unique in its ability to specifically promote increased vascular permeability, endothelial cell growth, and angio-genesis.

Podocyte loss and progressive glomerular injury in type II diabetes

Kidney biopsies from Pima Indians with type II diabetes were analyzed. Subjects were classified clinically as having early diabetes (n = 10), microalbuminuria (n = 17), normoalbuminuria, despite a duration of diabetes equal to that of the subjects with microalbuminuria (n = 12), or clinical nephropathy (n = 12). Subjects with microalbuminuria exhibited moderate increases in glomerular and mesangial volume when compared with those with early diabetes, but could not be distinguished from subjects who remained normoalbuminuric after an equal duration of diabetes. Subjects with clinical nephropathy exhibited global glomerular sclerosis and more prominent structural abnormalities in nonsclerosed glomeruli. Marked mesangial expansion was accompanied by a further increase in total glomerular volume. Glomerular capillary surface area remained stable, but the glomerular basement membrane thickness was increased and podocyte foot processes were broadened. Broadening of podocyte foot processes was associated with a reduction in the number of podocytes per glomerulus and an increase in the surface area covered by remaining podocytes. These findings suggest that podocyte loss contributes to the progression of diabetic nephropathy.

Effect of oral nimodipine on cerebral infarction and outcome after subarachnoid haemorrhage: British aneurysm nimodipine trial

OBJECTIVE

To determine the efficacy of oral nimodipine in reducing cerebral infarction and poor outcomes (death and severe disability) after subarachnoid haemorrhage.

DESIGN

Double blind, placebo controlled, randomised trial with three months of follow up and intention to treat analysis. To have an 80% chance with a significance level of 0.05 of detecting a 50% reduction in an incidence of cerebral infarction of 15% a minimum of 540 patients was required.

SETTING

Four regional neurosurgical units in the United Kingdom.

PATIENTS

In all 554 patients were recruited between June 1985 and September 1987 out of a population of 1115 patients admitted with subarachnoid haemorrhage proved by the results of lumbar puncture or computed tomography, or both. The main exclusion criterion was admission to the neurosurgical units more than 96 hours after subarachnoid haemorrhage. There were four breaks of code and no exclusions after entry. One patient was withdrawn and in 130 treatment was discontinued early. All patients were followed up for three months and were included in the analysis, except the patient who had been withdrawn.

INTERVENTIONS

Placebo or nimodipine 60 mg was given orally every four hours for 21 days to 276 and 278 patients, respectively. Treatment was started within 96 hours after subarachnoid haemorrhage.

END POINTS

Incidence of cerebral infarction and ischaemic neurological deficits and outcome three months after entry.

MEASUREMENTS

Demographic and clinical data, including age, sex, history of hypertension and subarachnoid haemorrhage, severity of haemorrhage according to an adaptation of the Glasgow coma scale, number and site of aneurysms on angiography, and initial findings on computed tomography were measured at entry. Deterioration, defined as development of a focal sign or fall of more than one point on the Glasgow coma scale for more than six hours, was investigated by using clinical criteria and by computed tomography, by lumbar puncture, or at necropsy when appropriate. All episodes of deterioration and all patients with a three month outcome other than a good recovery were assessed by a review committee.

MAIN RESULTS

Demographic and clinical data at entry were similar in the two groups. In patients given nimodipine the incidence of cerebral infarction was 22% (61/278) compared with 33% (92/276) in those given placebo, a significant reduction of 34% (95% confidence interval 13 to 50%). Poor outcomes were also significantly reduced by 40% (95% confidence interval 20 to 55%) with nimodipine (20% (55/278) in patients given nimodipine v 33% (91/278) in those given placebo).

CONCLUSIONS

Oral nimodipine 60 mg four hourly is well tolerated and reduces cerebral infarction snd improves outcome after subarachnoid haemorrhage.

Intracellular staining reveals different levels of stratification for on- and off-center ganglion cells in cat retina

1. Ganglion cells in the retina of the cat were stained by intracellular dye injection after recording their responses to photic stimulation. 2. All cells encountered were divided into those giving on-responses and those producing off-responses, and the level of dendritic branching of these two groups was compared. Cells giving off-responses were found to branch high in the inner plexiform layer (IPL), near the amacrine cell bodies (sublamina a); those giving on-responses were found to branch lower in the inner plexiform layer (sublamina b). 3. Dye-injected cells varied widely in morphology and size, having cell bodies ranging in diameter from 8 to 32 micrometer and dendritic fields ranging from 25 to 490 micrometer in diameter; yet the sign of the response of each unit correlated only with the level of dendritic branching. Thus, no other morphological feature except stratification appears to be important in determining the sign of the response of these cells. 4. The stratification of ganglion cells into on- and off-layers parallels the distribution of the axon terminals of the flat and invaginating cone bipolars. Flat cone bipolars are in a position to contact off-center ganglion cells (in sublamina a) and invaginating cone bipolars are in a position to contact on-center ganglion cells (in sublamina b). 5. The rod and cone inputs to some cells were characterized by comparing their responses to deep red and blue rod-matched stimuli over a 2-log unit range starting at dark-adapted threshold. About half the cells appeared to be rod dominated under these conditions, whereas the others appeared to have mixed rod and cone signals. 6. The nature of the rod and cone pathways to ganglion cells is discussed.

A full genome search in multiple sclerosis

The aetiology of multiple sclerosis (MS) is uncertain. There is strong circumstantial evidence to indicate it is an autoimmune complex trait. Risks for first degree relatives are increased some 20 fold over the general population. Twin studies have shown monozygotic concordance rates of 25-30% compared to 4% for dizygotic twins and siblings. Studies of adoptees and half sibs show that familial risk is determined by genes, but environmental factors strongly influence observed geographic differences. Studies of candidate genes have been largely unrewarding. We report a genome search using 257 microsatellite markers with average spacing of 15.2 cM in 100 sibling pairs (Table 1, data set 1 - DS1). A locus of lambda>3 was excluded from 88% of the genome. Five loci with maximum lod scores (MLS) of >1 were identified on chromosomes 2, 3, 5, 11 and X. Two additional data sets containing 44 (Table 1, DS2) and 78 sib pairs (Table 1, DS3) respectively, were used to further evaluate the HLA region on 6p21 and a locus on chromosome 5 with an MLS of 4.24. Markers within 6p21 gave MLS of 0.65 (non-significant, NS). However, D6S461, just outside the HLA region, showed significant evidence for linkage disequilibrium by the transmission disequilibrium test (TDT), in all three data sets (for DS1 chi2 = 10.8, adjusted P < 0.01)(DS2 and DS3 chi2 = 10.9, P < 0.0005), suggesting a modest susceptibility locus in this region. On chromosome 5p results from all three data sets (222 sib pairs) yielded a multipoint MLS of 1.6. The results support genetic epidemiological evidence that several genes interact epistatically to determine heritable susceptibility.

Ectopic induction of tendon and ligament in rats by growth and differentiation factors 5, 6, and 7, members of the TGF-beta gene family

Little is known about the regulatory signals involved in tendon and ligament formation, and this lack of understanding has hindered attempts to develop biologically based therapies for tendon and ligament repair. Here we report that growth and differentiation factors (GDFs) 5, 6, and 7, members of the TGF-beta gene superfamily that are most related to the bone morphogenetic proteins, induce neotendon/ligament formation when implanted at ectopic sites in vivo. Analysis of tissue induced by GDF-5, 6, or 7, containing implants by currently available morphological and molecular criteria used to characterize tendon and ligament, adds further evidence to the idea that these GDFs act as signaling molecules during embryonic tendon/ligament formation. In addition, comparative in situ localizations of the GDF-5, 6, and 7 mRNAs suggest that these molecules are important regulatory components of synovial joint morphogenesis.

Podocyte number predicts long-term urinary albumin excretion in Pima Indians with Type II diabetes and microalbuminuria

AIMS/HYPOTHESIS

The predictive value of glomerular structure on progression of renal disease was examined in patients with Type II (non-insulin-dependent) diabetes and microalbuminuria (urinary albumin-to-creatinine ratio = 30-299 mg/g).

METHODS

Kidney biopsy specimens were obtained from 16 diabetic Pima Indians (6 men, 10 women). Progression of renal disease was assessed by measuring urinary albumin excretion 4 years after the biopsy (UAE(4 years)) and by computing the change in urinary albumin excretion during the study (Delta UAE).

RESULTS

At baseline, the duration of diabetes averaged 13.3 years (range = 4.0-23.8 years) and the mean glomerular filtration rate was 159 ml x min(-1) x 1.73 m(-2) (range = 98 - 239 ml x min(-1) x 1.73 m(-2)). Median urinary albumin excretion was 67 mg/g (range = 25-136 mg/g) and it increased to 625 mg/g (range = 9-13471 mg/g) after 4 years; 10 subjects (63 %; 4 men, 6 women) developed macroalbuminuria (urinary albumin-to-creatinine ratio >/= 300 mg/g). Neither mean arterial pressure nor HbA(1 c) changed substantially during follow-up. Among the glomerular morphologic characteristics, the number of visceral epithelial cells, or podocytes, per glomerulus was the strongest predictor of renal disease progression (UAE(4 years), r = -0.49, p = 0.05; DeltaUAE, r = -0.57, p = 0.02), with fewer cells predicting more rapid progression. Glomerular basement membrane thickness did not predict progression (UAE(4 years), r = 0.11, p = 0.67; DeltaUAE, r = 0.09, p = 0.73) and mesangial volume fraction had only a modest effect (UAE(4 years,) r = 0.42, p = 0.11; DeltaUAE, r = 0.48, p = 0.06).

CONCLUSION/INTERPRETATION

Whether lower epithelial cell number per glomerulus among those that progressed was due to cellular destruction, a reduced complement of epithelial cells, or both is uncertain. Nevertheless, these findings suggest that podocytes play an important part in the development and progression of diabetic renal disease. [Diabetologia (1999) 42: 1341-1344]

Community-based prevalence of anal incontinence

OBJECTIVE

To determine the prevalence of and characteristics associated with anal incontinence in the general community.

SETTING

Community survey.

PARTICIPANTS

The population of the state of Wisconsin sampled in the Wisconsin Family Health Survey. Subjects were identified by random digit dialing with telephone interview. The individual within each household identified as most knowledgeable about the health status of all other members of the household was asked about the health status of each member of the household. Approximately 200 households were surveyed each month.

MAIN OUTCOME MEASURES

The presence of anal incontinence to solid or liquid feces or gas, who suffered from it, the frequency of anal incontinence, and how the incontinent person coped with it.

RESULTS

A total of 2570 households comprising 6959 individuals were surveyed, and 153 individuals were reported to have anal incontinence, representing 2.2% of the population (95% confidence interval [Cl], +/- 0.3%). Thirty percent of the incontinent subjects were older than 65 years, and 63% were women. Of those with anal incontinence, 36% were incontinent to solid feces, 54% to liquid feces, and 60% to gas. In a multivariate analysis, independent associations of the following risk factors with anal incontinence were found: female sex (odds ratio [OR], 1.5; Cl, 1.1 to 2.1), age (continuously adjusted) (OR, 1.01; Cl, 1.01 to 1.02), physical limitations (OR, 1.8; Cl, 1.2 to 2.7), and poor general health (OR, 1.6; Cl, 1.4 to 1.9).

CONCLUSIONS

Anal incontinence was reported in 2.2% of the general population. Independent risk factors for incontinence include female sex, advancing age, poor general health, and physical limitations.

Development and progression of renal disease in Pima Indians with non-insulin-dependent diabetes mellitus. Diabetic Renal Disease Study Group

BACKGROUND

Non-insulin-dependent diabetes mellitus (NIDDM) is a major cause of end-stage renal disease. However, the course and determinants of renal failure in this type of diabetes have not been clearly defined.

METHODS

We studied glomerular function at intervals of 6 to 12 months for 4 years in 194 Pima Indians selected to represent different stages in the development and progression of diabetic renal disease. Initially, 31 subjects had normal glucose tolerance, 29 had impaired glucose tolerance, 30 had newly diagnosed diabetes, and 104 had had diabetes for five years or more; of these 104, 20 had normal albumin excretion, 50 had microalbuminuria, and 34 had macroalbuminuria. The glomerular filtration rate, renal plasma flow, urinary albumin excretion, and blood pressure were measured at each examination.

RESULTS

Initially, the mean (+/-SE) glomerular filtration rate was 143+/-7 ml per minute in subjects with newly diagnosed diabetes, 155+/-7 ml per minute in those with microalbuminuria, and 124+/-7 ml per minute in those with macroalbuminuria; these values were 16 percent, 26 percent, and 1 percent higher, respectively, than in the subjects with normal glucose tolerance (123+/-4 ml per minute). During four years of follow-up, the glomerular filtration rate increased by 18 percent in the subjects who initially had newly diagnosed diabetes (P=0.008); the rate declined by 3 percent in those with microalbuminuria at base line (P=0.29) and by 35 percent in those with macroalbuminuria (P<0.001). Higher base-line blood pressure predicted increasing urinary albumin excretion (P=0.006), and higher base-line urinary albumin excretion predicted a decline in the glomerular filtration rate (P<0.001). The initial glomerular filtration rate did not predict worsening albuminuria.

CONCLUSIONS

The glomerular filtration rate is elevated at the onset of NIDDM and remains so while normal albumin excretion or microalbuminuria persists. It declines progressively after the development of macroalbuminuria.

Bcl-2 family proteins are essential for platelet survival

Platelets are relatively short-lived, anucleated cells that are essential for proper hemostasis. The regulation of platelet survival in the circulation remains poorly understood. The process of platelet activation and senescence in vivo is associated with processes similar to those observed during apoptosis in nucleated cells, including loss of mitochondrial membrane potential, caspase activation, phosphatidylserine (PS) externalization, and cell shrinkage. ABT-737, a potent antagonist of Bcl-2, Bcl-X(L), and Bcl-w, induces apoptosis in nucleated cells dependent on these proteins for survival. In vivo, ABT-737 induces a reduction of circulating platelets that is maintained during drug therapy, followed by recovery to normal levels within several days after treatment cessation. Whole body scintography utilizing ([111])Indium-labeled platelets in dogs shows that ABT-737-induced platelet clearance is primarily mediated by the liver. In vitro, ABT-737 treatment leads to activation of key apoptotic processes including cytochrome c release, caspase-3 activation, and PS externalization in isolated platelets. Despite these changes, ABT-737 is ineffective in promoting platelet activation as measured by granule release markers and platelet aggregation. Taken together, these data suggest that ABT-737 induces an apoptosis-like response in platelets that is distinct from platelet activation and results in enhanced clearance in vivo by the reticuloendothelial system.

The natural history of impaired glucose tolerance in the Pima Indians

Among 384 Pima Indians with impaired glucose tolerance according to World Health Organization criteria who were followed for 1.6 to 11.5 years (median, 3.3), non-insulin-dependent diabetes mellitus (NIDDM) developed in 118 (31 percent), glucose tolerance remained impaired in 100 (26 percent), and glucose tolerance returned to normal in 166 (43 percent). The cumulative incidence of NIDDM was 25 and 61 percent at 5 and 10 years, respectively. The risk of development of diabetes was 6.3 times (95 percent confidence interval, 3.8 to 10.6) as high as in a normoglycemic control group (n = 752). Variables predicting deterioration to NIDDM were age up to the age of 40, after which increasing age had a beneficial effect; higher plasma glucose levels during fasting and after carbohydrate loading; and higher serum insulin levels after fasting and lower levels after carbohydrate loading, suggesting that insulin resistance and decreased beta-cell responsiveness are important determinants of the clinical outcome of impaired glucose tolerance. Obese subjects had 2.9 times (95 percent confidence interval, 2.0 to 10.9) the incidence of NIDDM as the nonobese. Obesity was not, however, predictive of progression to NIDDM after an adjustment for plasma glucose and serum insulin levels. We conclude that in this population approximately one fourth of subjects with impaired glucose tolerance have NIDDM at five years and two thirds at 10 years (approximately one third revert to normal) and that age and plasma glucose and insulin levels are the best predictors of clinical outcome.

Cat cones have rod input: a comparison of the response properties of cones and horizontal cell bodies in the retina of the cat

The responses of horizontal cell bodies and cones in the retina of the cat have been studied by means of intracellular recording and Procion dye injection in an isolated, arterially perfused eyecup preparation. Comparison of the hyperpolarizing responses of these units to red and blue stimuli of different intensities indicated that all morphological varieties of horizontal cells and, additionally, cones themselves, had mixed rod and cone input. The rod input into horizontal cell bodies is thus explained on the basis of cone physiology. The half-saturating intensity of 441 nm stimuli for the rod input into cones and horizontal cells was about 400 quanta/mum2/sec and about 160,000 quanta/mum2/sec for the cone input. Little of this difference can be related to the different quantum catching abilities of rods and cones. The spatial properties of horizontal cell bodies and cones have been characterized using stimuli consisting of long slits in conjunction with a continuous cable model. Space constants for horizontal cells ranged from 210 mum to 410 mum, whereas those for cones ranged from 50 mum, or possibly less, to 180 mum. It is argued that horizontal cell bodies of the cat retina form electrical networks, and that the sizes of the receptive fields generated in these networks may be limited by the diameters of the primary and secondary dendrites of horizontal cells. The rod and cone fields of horizontal cell bodies were found to be nearly coextensive in space, arguing against the notion that substantial rod input came from distant, rod-dominated terminal arborizations.

Cloning and sequence analysis of a highly polymorphic Cryptosporidium parvum gene encoding a 60-kilodalton glycoprotein and characterization of its 15- and 45-kilodalton zoite surface antigen products

The apicomplexan parasite Cryptosporidium parvum is a major cause of serious diarrheal disease in both humans and animals. No efficacious chemo- or immunotherapies have been identified for cryptosporidiosis, but certain antibodies directed against zoite surface antigens and/or proteins shed by gliding zoites have been shown to neutralize infectivity in vitro and/or to passively protect against, or ameliorate, disease in vivo. We previously used monoclonal antibody 11A5 to identify a 15-kDa surface glycoprotein that was shed behind motile sporozoites and was recognized by several lectins that neutralized parasite infectivity for cultured epithelial cells. Here we report the cloning and sequence analysis of the gene encoding this 11A5 antigen. Surprisingly, the gene encoded a 330-amino-acid, mucin-like glycoprotein that was predicted to contain an N-terminal signal peptide, a homopolymeric tract of serine residues, 36 sites of O-linked glycosylation, and a hydrophobic C-terminal peptide specifying attachment of a glycosylphosphatidylinositol anchor. The single-copy gene lacked introns and was expressed during merogony to produce a 60-kDa precursor which was proteolytically cleaved to 15- and 45-kDa glycoprotein products that both localized to the surface of sporozoites and merozoites. The gp15/45/60 gene displayed a very high degree of sequence diversity among C. parvum isolates, and the numerous single-nucleotide and single-amino-acid polymorphisms defined five to six allelic classes, each characterized by additional intra-allelic sequence variation. The gp15/45/60 single-nucleotide polymorphisms will prove useful for haplotyping and fingerprinting isolates and for establishing meaningful relationships between C. parvum genotype and phenotype.

Periodontal disease and NIDDM in Pima Indians

The goal of this study was to determine the prevalence and incidence of periodontal disease and its relationship with non-insulin-dependent diabetes mellitus (NIDDM). Two thousand two hundred seventy-three Pima Indians (949 men, 1324 women) aged greater than or equal to 15 yr from the Gila River Indian Community in Arizona were examined between 1983 and 1989. Periodontal disease was diagnosed by tooth loss and by percentage of interproximal crestal alveolar bone loss ascertained from panoramic radiography. Subjects with little or no evidence of periodontal disease were classified as nondiseased. Thus, the incidence of advanced periodontal disease was determined. The age- and sex-adjusted prevalence of periodontal disease at first dental examination was 60% in subjects with NIDDM and 36% in those without. Twenty-two new cases developed in a subset of 701 subjects (272 men, 429 women) aged 15-54 yr who initially had little or no evidence of periodontal disease and had at least one additional dental examination. The incidence of periodontal disease in this group was similar in men and women (incidence-rate ratio 1.0, 95% confidence interval [Cl] 0.5-1.9, controlled for age and diabetes). Higher age predicted a greater incidence of periodontal disease (chi 2 = 30.6, df = 3, P less than 0.001, controlled for sex and diabetes). The rate of periodontal disease in subjects with diabetes was 2.6 times (95% Cl 1.0-6.6, controlled for age and sex) that observed in those without. Although periodontal disease was common in nondiabetic Pima Indians, in whom most of the incident cases occurred, diabetes clearly conferred a substantially increased risk. Thus, periodontal disease should be considered a nonspecific complication of NIDDM.

Familial predisposition to renal disease in two generations of Pima Indians with type 2 (non-insulin-dependent) diabetes mellitus

We studied the occurrence of renal disease by measuring serum creatinine and urine protein concentrations in the diabetic members of 316 Pima Indian families with Type 2 (non-insulin-dependent) diabetes in two successive generations to determine if diabetic renal disease aggregates in families. After adjustment for sex and other risk factors, proteinuria occurred among 14.3% of the diabetic offspring if neither parent had proteinuria, 22.9% if at least one diabetic parent had proteinuria, and 45.9% if both parents had diabetes and proteinuria. Among male offspring, an elevated serum creatinine concentration (greater than or equal to 177 mumol/l) was present in 11.7% if the parent had an elevated creatinine and in 1.5% if the parent did not. Thus, proteinuria and high serum creatinine aggregated in diabetic families, suggesting that susceptibility to renal disease is inherited independently of diabetes.

Long-term reversal of diabetes by the injection of immunoprotected islets

The intraperitoneal injection of insulin-producing islets immunoprotected by an alginate-poly(amino acid) membrane is a potential method of reversing diabetes without the need for lifelong immunosuppression. Previous attempts to demonstrate this technology in large animals have failed, preventing application in humans. We have determined that key factors responsible for these past failures include cytokine (interleukins 1 and 6 and tumor necrosis factor) stimulation by mannuronic acid monomers from alginate capsules with weak mechanical integrity, which results in fibroblast proliferation. With this insight, we formulated mechanically stable microcapsules by using alginate high in guluronic acid content and report prolonged reversal of diabetes in the spontaneous diabetic dog model by the intraperitoneal injection of encapsulated canine islet allografts. Euglycemia, independent of any exogenous insulin requirement, was noted for up to 172 days. Graft survival, evidenced by positive C-peptide release, was noted for as long as 726 days in a recipient receiving a single injection of immunoprotected islets. Histological evidence of viable islets retrieved from the peritoneal cavity 6 months posttransplant confirmed the biocompatibility and immunoprotective nature of this capsule formulation. The finding that intraperitoneal injection of alginate-immunoprotected islets, a minimally invasive surgical procedure, is effective in prolonged (> 1 year) maintenance of glycemic control, without the need for lifelong immunosuppression, may have significant implications for the future therapy of type I diabetes in humans.

Obesity in the Pima Indians: its magnitude and relationship with diabetes

Members of the Pima Indian population are obese, on average, as estimated by the body mass index (BMI). Young adults have had the highest BMIs and there have been modest increases in age- and sex-specific mean BMIs for the past 25 y. These observations suggest that the older adults have had less exposure to factors leading to obesity than have the younger adults. Compared with children studied early in this century, present-day Pima children are much heavier for height, suggesting that the degree of obesity has increased since that time. Obesity in the Pimas is familial and has complex relationships with non-insulin-dependent diabetes mellitus, a common disease in this population. Obesity predicts the development of diabetes; once people have diabetes, however, they tend to lose weight. Thus, obesity should not be studied in this population without also considering diabetes, which tends to limit the degree of obesity.

Synaptic patterns and response properties of bipolar and ganglion cells in the cat retina

After intracellular recording, bipolar cells of the cat retina have been stained with HRP and their contacts in the outer and inner plexiform layers examined by electron microscopy. Rod bipolars and cone bipolar cb6 make invaginating, ribbon related contacts with photoreceptors, hyperpolarize in response to light, and have axons terminating in layer b of the IPL. The axon terminal of cb2 ends in layer a of the IPL and its basal contacts with cones mediate hyperpolarizing light-responses. Cone bipolar cb5 is a center-depolarizing type with an axon ending in layer b but its cone contacts are at semi-invaginating basal junctions. Except for the amacrine-contacting rod bipolar cell, all cone bipolar types synapse with both amacrine and ganglion cells in the inner plexiform layer. In addition cb5 contacts AII amacrine cells with large gap junctions, and is physiologically rod dominated.

Sequential changes in serum insulin concentration during development of non-insulin-dependent diabetes

Changes in serum insulin concentrations during deterioration of glucose tolerance were studied in 81 Pima Indians who worsened from normal to impaired glucose tolerance (IGT); 44 who changed from IGT to non-insulin-dependent diabetes mellitus (NIDDM); 27 who were seen at diagnosis of NIDDM and 1.4-8.5 years later; and 11 subjects who were seen at each of these stages. When their glucose tolerance was normal, subjects who later developed NIDDM had higher fasting and post-load insulin concentrations than controls of similar age and body mass index who did not become diabetic. Onset of IGT or NIDDM was associated with a further increase in fasting insulin concentrations, although a deterioration from IGT to NIDDM was associated with little change in insulin responses to oral glucose in spite of increased blood glucose. After the onset of NIDDM, both fasting and post-load insulin concentrations diminished. These longitudinal data show that, as glucose tolerance worsens, insulin and glucose concentrations in individuals follow the inverted-U-shaped relation previously reported in cross-sectional population studies.

Diabetes and obesity in the offspring of Pima Indian women with diabetes during pregnancy

OBJECTIVE

To review the long-term effects of the diabetic pregnancy on the offspring among the Pima Indians of Arizona.

RESEARCH DESIGN AND METHODS

Studies published by the Phoenix Epidemiology and Clinical Research branch of the National Institute of Diabetes and Digestive and Kidney Diseases, since the inception of the longitudinal diabetes studies in 1965 were reviewed. In addition, pertinent studies from other centers, mentioned as references in these publications, were reviewed. As far as possible, all original articles and abstracts on this aspect of the Pima Indian studies were discussed.

RESULTS

The offspring of women who had diabetes during pregnancy, on average, were more obese and had higher glucose concentrations and more diabetes than the offspring of women who developed diabetes after pregnancy or who remained nondiabetic. Although no new analyses were attempted, several of the older publications were updated by repeating the analyses on later, expanded data sets.

CONCLUSIONS

The diabetic pregnancy, in addition to its effects on the newborn, has effects on the subsequent growth and glucose metabolism of the offspring. These effects are in addition to genetically determined traits.

Successful reversal of spontaneous diabetes in dogs by intraperitoneal microencapsulated islets

Long-term euglycemia by intraperitoneal transplantation of microencapsulated islets has not been described in the diabetic large animal model. In this study, we report the successful long-term reversal of diabetes by this method in spontaneous diabetic dogs. We have identified fundamental mechanism(s) associated with alginate-based microcapsule fibrosis, and have devised methods to ameliorate this problem. These include the use of purified alginate of low mannuronic acid content and cytokine suppression. Ten insulin-dependent, spontaneous diabetic dogs (insulin requirement 1-4 units/kg/day; absence of circulating C-peptide and diabetic K-values of 0.6 +/- 0.4) were entered into the study. Islets from mongrel donor pancreata were isolated and transplanted intraperitoneally either as free islet controls (n = 3) or as microencapsulated islet allografts (n = 7). In all seven encapsulated islet recipients, euglycemia was achieved within 24 hr (serum glucose failing from 304 +/- 117 to 116 +/- 72 mg/dl). IVGTT performed 14 days after islet transplant demonstrated normalization of K-values changing from a pretransplant level of 0.6 +/- 0.4 to 2.6 +/- 0.6. All animals receiving encapsulated islets remained euglycemic, free of the need for exogenous insulin, for a period of 63-172 days, with a median insulin-independence for 105 days. In contrast, recipients receiving free islets rejected their graft within seven days of implantation. In conclusion, this is the first report of long-term successful reversal of spontaneous diabetes in the large animal model by an intraperitoneal injection of encapsulated islets. The potential exists for this form of therapy to be explored in the treatment of type I diabetes in man.

Incidence of end-stage renal disease in type 2 (non-insulin-dependent) diabetes mellitus in Pima Indians

The incidence of end-stage renal disease was determined in the Pima Indians of the Gila River Indian Community in Arizona, a population with a high prevalence of Type 2 (non-insulin-dependent) diabetes mellitus. Between 1975 and 1986, from a study population of 5059 subjects, end-stage renal disease occurred in 80 persons, 76 (95%) of whom had Type 2 diabetes. A review of the cases with end-stage renal disease indicated that among the diabetic subjects only two cases could be attributed to nondiabetic renal disease; all other cases were attributable to diabetic nephropathy. In diabetic Pima Indians the incidence rate of end-stage renal disease did not change during the study period, was similar in men and women, and was not effected by age at diagnosis of diabetes or by attained age, but did increase significantly with hypertension (p less than 0.05). The incidence of end-stage renal disease attributed to diabetic nephropathy increased from 0 cases/1000 person-years at 0-5 years to 40.8 cases/1000 person-years at greater than or equal to 20 years duration of diabetes. In these subjects with Type 2 diabetes, the incidence rate of end-stage renal disease was similar to that in subjects with Type 1 (insulin-dependent) diabetes who were followed at the Joslin Clinic in Boston, Massachusetts when those with similar duration of diabetes were compared.