Baseline characteristics of participants in the Kerala Diabetes Prevention Program: a cluster randomized controlled trial of lifestyle intervention in Asian Indians.

AIMS: To describe the baseline characteristics of participants in the Kerala Diabetes Prevention Program. METHODS: The Kerala Diabetes Prevention Program is a cluster randomized controlled trial of lifestyle intervention for prevention of Type 2 diabetes mellitus in India. Participants in the study were those aged 30-60 years who had an Indian Diabetes Risk Score ≥ 60 and who were without Type 2 diabetes on oral glucose tolerance test. Data on demographic, lifestyle, clinical and biochemical characteristics were collected using standardized tools. RESULTS: A total of 2586 individuals were screened with the Indian Diabetes Risk Score, of these 1529 people (59.1%) had a score ≥ 60, of whom 1209 (79.1%) underwent an oral glucose tolerance test. A total of 202 individuals (16.7%) had undiagnosed Type 2 diabetes and were excluded, and the remaining 1007 individuals were enrolled in the trial (control arm, n = 507; intervention arm, n = 500). The mean participant age was 46.0 ± 7.5 years, and 47.2% were women. The mean Indian Diabetes Risk Score was 67.1 ± 8.4. More than two-thirds (69.0%) had prediabetes and 31.0% had normal glucose tolerance. The prevalence of cardiometabolic risk factors was high, including current tobacco use (34.4% in men), current alcohol use (39.3% in men), no leisure time exercise (98.0%), no daily intake of fruit and vegetables (78.7%), family history of diabetes (47.9%), overweight or obesity (68.5%), hypertension (22.3%) and dyslipidemia (85.4%). CONCLUSIONS: The Kerala Diabetes Prevention Program recruited participants using a diabetes risk score. A large proportion of the participants had prediabetes and there were high rates of cardiometabolic risk factors. The trial will evaluate the effectiveness of lifestyle intervention in a population selected on the basis of a diabetes risk score.

The Association of Type 2 Diabetes Mellitus with Cerebral Gray Matter Volume Is Independent of Retinal Vascular Architecture and Retinopathy.

It is uncertain whether small vessel disease underlies the relationship between Type 2 Diabetes Mellitus (T2DM) and brain atrophy. We aimed to study whether retinal vascular architecture, as a proxy for cerebral small vessel disease, may modify or mediate the associations of T2DM with brain volumes. In this cross-sectional study using Magnetic Resonance Imaging (MRI) scans and retinal photographs in 451 people with and without T2DM, we measured brain volumes, geometric measures of retinal vascular architecture, clinical retinopathy, and MRI cerebrovascular lesions. There were 270 people with (mean age 67.3 years) and 181 without T2DM (mean age 72.9 years). T2DM was associated with lower gray matter volume (p = 0.008). T2DM was associated with greater arteriolar diameter (p = 0.03) and optimality ratio (p = 0.04), but these associations were attenuated by adjustments for age and sex. Only optimality ratio was associated with lower gray matter volume (p = 0.03). The inclusion of retinal measures in regression models did not attenuate the association of T2DM with gray matter volume. The association of T2DM with lower gray matter volume was independent of retinal vascular architecture and clinical retinopathy. Retinal vascular measures or retinopathy may not be sufficiently sensitive to confirm a microvascular basis for T2DM-related brain atrophy.

Retinal arteriolar narrowing and incidence of knee replacement for osteoarthritis: a prospective cohort study.

OBJECTIVES: The role of the microcirculation in the pathogenesis of osteoarthritis (OA) remains unclear. This prospective cohort study examined the association between retinal vascular calibre and incidence of knee replacement for OA. DESIGN: 1838 participants of the Australian Diabetes, Obesity and Lifestyle (AusDiab) Study had retinal vascular calibre measured using a nonmydriatic digital fundus camera in 1999-2000 and were aged ≥ 40 years at joint replacement data collection commencement. The incidence of knee replacement for OA during 2002-2011 was determined by linking cohort records to the Australian Orthopaedic Association National Joint Replacement Registry (AOANJRR). RESULTS: 77 participants underwent knee replacement for OA. They had narrower retinal arteriolar calibre compared with those without knee replacement (166.1 ± 24.8 µm vs 174.3 ± 24.5 µm, P = 0.004). For every one standard deviation reduction in retinal arteriolar calibre, the incidence of knee replacement increased by 25% (HR 1.25, 95% confidence interval (CI) 1.00-1.56). Participants in the narrower two-thirds of arteriolar calibre had twice the risk of knee replacement compared with those in the widest one-third (HR 2.00, 95% CI 1.07-3.74, P = 0.03) after adjustment for sex, body mass index (BMI), physical activity and HbA1c. There was no association for retinal venular calibre. CONCLUSIONS: Retinal arteriolar narrowing is associated with increased risk of knee replacement for OA suggesting that further work is warranted to determine the role of the microcirculation in the pathogenesis of knee OA.

Health behaviours, socioeconomic status and diabetes incidence: the Australian Diabetes Obesity and Lifestyle Study (AusDiab).

AIMS/HYPOTHESIS: To identify the impact of socioeconomic status on incident impaired glucose metabolism and type 2 diabetes and to investigate the mediating role of health behaviours on this relationship using national, population-based data. METHODS: The Australian Diabetes Obesity and Lifestyle (AusDiab) Study is a national, population-based, longitudinal study of adults aged 25 years and above. A total sample of 4,405 people provided complete baseline (1999-2000) and 5 year follow-up (2004-2005) data relevant for these analyses. Fasting plasma glucose and 2 h plasma glucose were obtained from an OGTT, and demographic, socioeconomic and behavioural data were collected by interview and questionnaire. Multinomial logistic regression examined the role of socioeconomic position in the development of diabetes and mediation analyses tested the contribution of health behaviours in this relationship. RESULTS: Highest level of education was a stronger predictor of incident impaired glucose tolerance and type 2 diabetes (p = 0.002), compared with household income (p = 0.103), and occupational grade (p = 0.202). Education remained a significant independent predictor of diabetes in fully adjusted models. However, the relationship was attenuated by the health behaviours (smoking and physical activity). Mediation analyses indicated that these behaviours were partial mediators (explaining 27%) of the socioeconomic status-diabetes relationship. CONCLUSION/INTERPRETATION: Smoking and physical activity partly mediate the relationship between low education and type 2 diabetes. Identification of these modifiable behavioural mediators should facilitate the development of effective health promotion campaigns to target those at high risk of developing type 2 diabetes.

The relationship of retinal vascular calibre to diabetes and retinopathy: the Australian Diabetes, Obesity and Lifestyle (AusDiab) study.

AIMS/HYPOTHESIS: The aim of the study was to examine the relationship of retinal vascular calibre with glucose intolerance, diabetes and retinopathy in a population-based cohort. METHODS: The Australian Diabetes, Obesity and Lifestyle study recruited adults aged > or =25 years old from across Australia. Participants were classified using an oral glucose tolerance test as having normal glucose tolerance (NGT), impaired glucose tolerance (IGT), impaired fasting glucose (IFG), known diabetes or newly diagnosed diabetes. Digital retinal photographs were taken of all participants with diabetes, IGT and IFG, and a sample of those with NGT, and graded for the presence of retinopathy. Retinal vascular calibre was measured from photographs by a computer-assisted method. RESULTS: Of the 1,998 participants with gradable retinal images, 16% had known diabetes, 17% newly diagnosed diabetes, 42% IGT, 6% IFG and 19% NGT. After multivariable adjustment, retinal arteriolar calibre was significantly larger in people with known diabetes (178.9 microm) compared with participants with NGT (174.6 microm, p = 0.02), IGT/IFG (175.5 microm, p = 0.02) or newly diagnosed diabetes (175.6 microm, p = 0.047). One SD increase in mean arteriolar calibre was associated with higher odds of diabetes compared with NGT (odds ratio [OR] = 1.28, 95%CI = 1.06-1.55). After multivariable adjustment, each SD increase in venular calibre was associated with higher odds of having retinopathy in persons with IGT/IFG (OR = 1.78, 95%CI = 1.36-2.34) or in persons with diabetes (OR = 1.68, 95%CI = 1.23-2.29). CONCLUSIONS/INTERPRETATION: Diabetes is associated with larger retinal arteriolar calibre and retinopathy with larger retinal venular calibre. The contrasting associations may reflect different underlying pathophysiological processes in the natural history of diabetes.

Diagnostic thresholds for diabetes: the association of retinopathy and albuminuria with glycaemia.

AIM: We examined the association of fasting plasma glucose (FPG), 2-h plasma glucose (2hPG) and HbA1c with retinopathy and microalbuminuria using both deciles of glycaemia and change point models, to validate current diagnostic criteria for diabetes and to identify therapeutic thresholds for glycaemic control. METHODS: The Australian Diabetes Obesity and Lifestyle study (AusDiab), conducted in 1999-2000, included adults aged > or =25 years from 42 randomly selected areas of Australia. Retinopathy and albuminuria were assessed in participants identified as having diabetes (based on self report and oral glucose tolerance test), impaired fasting glucose, impaired glucose tolerance and in a random sample with normal glucose tolerance. Data were available for 2,182 participants with retinal photographs and 2,389 with urinary albumin/creatinine results. RESULTS: The prevalence of retinopathy in the first 8 deciles of FPG and HbA1c and the first 9 deciles of 2hPG were 7.2, 6.6, and 6.3%, respectively and showed no variation with increasing glucose or HbA1c. Above these levels, the prevalence rose markedly to 18.6% in the top 2 deciles of FPG, 21.3% in the top 2 deciles of HbA1c and 10.9% in the top decile of 2hPG. The thresholds for increasing prevalence of retinopathy were 7.1 mmol/l for FPG, 6.1% for HbA1c and 13.1 mmol/l for 2hPG. The prevalence of microalbuminuria rose gradually across deciles of each glycaemic measure. Thresholds were less clear than for retinopathy, but were seen at a FPG of 7.2 mmol/l and HbA1c of 6.1%, with no evidence of a threshold effect for 2hPG. CONCLUSIONS: The prevalence of retinopathy rose dramatically in the highest deciles of each glycaemic measure, while for microalbuminuria the increase of prevalence was more gradual. The FPG values corresponded well with the WHO diagnostic cut-point for diabetes, however the 2hPG value did not. HbA1c thresholds were similar for both retinopathy and microalbuminuria and compared well to values shown in other studies. These results support current targets for FPG and HbA1c in preventing microvascular complications.

Foot complications in Type 2 diabetes: an Australian population-based study.

AIMS: To determine the prevalence and risk factors for neuropathy and peripheral vascular disease (PVD) in the Australian diabetic population and identify those at high risk of foot ulceration. METHODS: The Australian Diabetes Obesity and Lifestyle study included 11 247 adults aged >or= 25 years in 42 randomly selected areas of Australia. Neuropathy and PVD were assessed in participants identified as having diabetes (based on self report and oral glucose tolerance test), impaired fasting glucose, impaired glucose tolerance and in a random sample with normal glucose tolerance (total n = 2436). RESULTS: The prevalence of peripheral neuropathy was 13.1% in those with known diabetes (KDM) and 7.1% in those with newly diagnosed (NDM). The prevalence of PVD was 13.9% in KDM and 6.9% in NDM. Of those with diabetes, 19.6% were at risk of foot ulceration. Independent risk factors for peripheral neuropathy were diabetes duration (odds ratio (95% CI) 1.73 (1.33-2.28) per 10 years), height (1.42 (1.08-1.88) per 10 cm), age (2.57 (1.94-3.40) per 10 years) and uric acid (1.59 (1.21-2.09) per 0.1 mmol/l). Risk factors for PVD were diabetes duration (1.64 (1.25-2.16) per 10 years), age (2.45 (1.86-3.22) per 10 years), smoking (2.07 (1.00-4.28)), uric acid (1.03 (1.00-1.06) per 0.1 mmol/l) and urinary albumin/creatinine ratio (1.11 (1.01-1.21) per 1 mg/mmol). CONCLUSIONS: The prevalence of neuropathy and PVD was lower in this population than has been reported in other populations. This may reflect differences in sampling methods between community and hospital-based populations. Nevertheless, a substantial proportion of the diabetic population had risk factors for foot ulceration.

Differential detection of Bartonella species and strains in cat scratch disease diagnostics by polymerase chain reaction amplification of 16S ribosomal RNA gene.

Cat scratch disease (CSD) has been difficult to diagnose in animals because of the protracted clinical course of infection and the quiescent phases when the microbial culprit lies dormant. The causative agent in CSD appears to be multiple species and strains of Bartonella. Using polymerase chain reaction (PCR) techniques for amplification of highly variable regions of the 16S ribosomal RNA (rRNA) gene sequence, a very sensitive species- and strain-specific assay for CSD-causing Bartonella species was developed. PCR primers were designed to specifically amplify the 16S rRNA gene of Bartonella species but not of other microbial pathogens. This initial PCR was multiplexed with a universal primer set, based on conserved sequence regions in the 16S rRNA gene, that provides a 162-bp fragment in all species tested. Subsequently, 3 distinct nested PCR primer sets enabled the individual amplification and specific detection of Bartonella henselae type 1, B. henselae type II, and B. clarridgeae. Thus, this 2-step PCR procedure enabled the sensitive detection and identification of these species and the B. henselae genotype by exploiting minor sequences differences. Verification of these results were demonstrated with both sequencing and ligase chain reaction techniques. The diagnostic usefulness of this CSD test has been demonstrated by the analysis of specimens from control and infected cats. The diagnosis was confirmed and the specific B. henselae strain was correctly identified in peripheral blood specimens obtained from control and strain-specific CSD-infected cats. Such an accurate and sensitive diagnostic tool for the detection and identification of CSD causative agents should be a useful for the medical, veterinary, and scientific communities.

Evaluation and use of a nested polymerase chain reaction assay in cats experimentally infected with Bartonella henselae genotype I and Bartonella henselae genotype II.

Cats have been shown to be infected with Bartonella henselae genotype I, B. henselae genotype II, and B. clarridgeiae. Feline bartonellosis infections and the strains involved in these infections are important in both veterinary and human medicine. Nucleic acid amplification methods such as polymerase chain reaction (PCR) are being used in both research and diagnostics as tools for understanding many infectious diseases. Bartonella bacteremia in cats is detected by blood culture; however, because of the limitations of culture (delayed turnaround time and sensitivity limits), PCR may be a more efficient method for identifying infected cats. Three distinct PCR assays that could differentiate among B. henselae genotype I, B. henselae genotype II. and B. clarridgeiae were developed and used to detect as few as 3.2 organisms. Fourteen cats experimentally infected with B. henselae genotype I and B. henselae genotype II were followed by bacterial culture and PCR through the course of infection, including periods of primary and relapsing bacteremia. The PCR assay was positive in 11 of the 14 cats for periods of 1-9 weeks after culture became negative. Of the 223 blood specimens that were culture negative, the PCR assay was positive in 38 (17%) of the specimens. Two of the 14 cats developed relapsing bacteremia. The 2 B. henselae genotypes were amplified in the cats and the bacteremic phase of these infections as determined by PCR lasted for a longer period than previously determined by culture. Using laboratory assays such as PCR to understand the strains involved in feline bartonellosis and the course of the infection is important in the understanding of these zoonotic agents.

Expression of Kv1 potassium channels in mouse hippocampal primary cultures: development and activity-dependent regulation.

Excitability and discharge behavior of neurons depends on the highly variable expression pattern of voltage-dependent potassium (Kv) channels throughout the nervous system. To learn more about distribution, development, and activity-dependent regulation of Kv channel subunit expression in the rodent hippocampus, we studied the protein expression of members of the Kv1 subfamily in mouse hippocampus in situ and in primary cultures. In adult hippocampus, Kv1 (1-6) channel alpha-subunits were present, whereas at postnatal day 2, none of these proteins could be detected in CA1-CA3 and dentate gyrus. Kv1.1 was the first channel to be observed at postnatal day 6. The delayed postnatal expression and most of the subcellular distribution observed in hippocampal sections were mimicked by cultured hippocampal neurons in which Kv channels appeared only after 10 days in vitro. This developmental upregulation was paralleled by a dramatic increase in total K(+) current, as well as an elevated GABA release in the presence of 4-aminopyridine. Thus, the developmental profile, subcellular localization, and functionality of Kv1 channels in primary culture of hippocampus closely resembles the in situ situation. Impairing secretion by clostridial neurotoxins or blocking activity by tetrodotoxin inhibited the expression of Kv1.1, Kv1.2, and Kv1.4, whereas the other Kv1 channels still appeared. This activity-dependent depression was only observed before the initial appearance of the respective channels and lost after they had been expressed. Our data show that hippocampal neurons in culture are a convenient model to study the developmental expression and regulation of Kv1 channels. The ontogenetic regulation and the activity-dependent expression of Kv1.1, Kv1.2, and Kv1.4 indicate that neuronal activity plays a crucial role for the development of the mature Kv channel pattern in hippocampal neurons.

SNAP-25 requirement for dendritic growth of hippocampal neurons.

Structure and dimension of the dendritic arbor are important determinants of information processing by the nerve cell, but mechanisms and molecules involved in dendritic growth are essentially unknown. We investigated early mechanisms of dendritic growth using mouse fetal hippocampal neurons in primary culture, which form processes during the first week in vitro. We detected a key component of regulated exocytosis, SNAP-25 (synaptosomal associated protein of 25 kDa), in axons and axonal terminals as well as in dendrites identified by the occurrence of the dendritic markers transferrin receptor and MAP2. Selective inactivation of SNAP-25 by botulinum neurotoxin A (BoNTA) resulted in inhibition of axonal growth and of vesicle recycling in axonal terminals. In addition, dendritic growth of hippocampal pyramidal and granule neurons was significantly inhibited by BoNTA. In contrast, cleavage of synaptobrevin by tetanus toxin had an effect on neither axonal nor dendritic growth. Our observations indicate that SNAP-25, but not synaptobrevin, is involved in constitutive axonal growth and dendrite formation by hippocampal neurons.

Developmental expression of sodium entry pathways in rat nephron.

During the past several years, sites of expression of ion transport proteins in tubules from adult kidneys have been described and correlated with functional properties. Less information is available concerning sites of expression during tubule morphogenesis, although such expression patterns may be crucial to renal development. In the current studies, patterns of renal axial differentiation were defined by mapping the expression of sodium transport pathways during nephrogenesis in the rat. Combined in situ hybridization and immunohistochemistry were used to localize the Na-Pi cotransporter type 2 (NaPi2), the bumetanide-sensitive Na-K-2Cl cotransporter (NKCC2), the thiazide-sensitive Na-Cl cotransporter (NCC), the Na/Ca exchanger (NaCa), the epithelial sodium channel (rENaC), and 11beta-hydroxysteroid dehydrogenase (11HSD). The onset of expression of these proteins began in post-S-shape stages. NKCC2 was initially expressed at the macula densa region and later extended into the nascent ascending limb of the loop of Henle (TAL), whereas differentiation of the proximal tubular part of the loop of Henle showed a comparatively retarded onset when probed for NaPi2. The NCC was initially found at the distal end of the nascent distal convoluted tubule (DCT) and later extended toward the junction with the TAL. After a period of changing proportions, subsegmentation of the DCT into a proximal part expressing NCC alone and a distal part expressing NCC together with NaCa was evident. Strong coexpression of rENaC and 11HSD was observed in early nascent connecting tubule (CNT) and collecting ducts and later also in the distal portion of the DCT. Ontogeny of the expression of NCC, NaCa, 11HSD, and rENaC in the late distal convolutions indicates a heterogenous origin of the CNT. These data present a detailed analysis of the relations between the anatomic differentiation of the developing renal tubule and the expression of tubular transport proteins.

Normalizing the expression of nitric oxide synthase by low-dose AT1 receptor antagonism parallels improved vascular morphology in hypertensive rats.

In essential hypertension, stroke and kidney damage may result from an impaired interaction of vasoregulatory systems. Stroke-prone spontaneously hypertensive rats (SHRSP) were studied to analyze the effects of a low-dose treatment of the angiotensin II type 1 receptor (AT1) blocker candesartan cilexetil on the expression of nitric oxide synthases (NOS) and on vascular structure. Both treated and untreated SHRSP were kept on a stroke-promoting dietary regimen, and compared with Wistar Kyoto rats (WKY). Early mortality of untreated SHRSP was prevented by the treatment. In untreated SHRSP, cerebral intraparenchymal vessels of the parietal lobe showed lesions of the vascular wall and its periphery, such as proteinaceous deposits, perivascular dilated spaces, increase in phagocytic cells, and decreased actin immunostaining. Renal lesions were more pronounced comprising arteriolar occlusion, extensive loss of actin, increased alpha1(IV) collagen expression, and glomerular sclerotic as well as tubulointerstitial lesions. Beneficial effects of the AT1 blockade were more pronounced in brain than in kidney. Activity profile of NOS showed increased NADPH diaphorase staining in media and endothelium of SHRSP; endothelial NOS3 immunoreactivity was decreased, but instead, inducible NOS2 increased in untreated SHRSP. These changes were largely prevented in the treated group. NOS activity in macula densa cells was unchanged, whereas afferent arteriolar renin levels were increased in untreated SHRSP. Results demonstrate an effective reduction of hypertensive vascular changes with a nonpressor dose of candesartan. A "role switch" of vascular NOS in hypertension from physiologic NOS3 toward deleterious NOS2 is suggested, and its prevention by the AT1 blocker points to an angiotensin II-dependent, nitric oxide-mediated pathway that may impair endothelial function and aggravate defects of the blood-brain barrier and kidney structures.

Prenatal hippocampal granule cells in primary cell culture form mossy fiber boutons at pyramidal cell dendrites.

Mossy fiber boutons are the sites of synaptic signalling between hippocampal granule and pyramidal neurons. We studied the formation and localization of these terminals during development of prenatal hippocampal neurons in primary culture. Using the synaptic vesicle membrane proteins synaptophysin and synaptoporin as markers we observed that both proteins were mainly localized in perikarya and processes of fetal hippocampal neurons during the first days in vitro (DIV). Following DIV 6 synaptophysin was present in small terminals. After DIV 20 in addition large terminals immunoreactive for synaptophysin and synaptoporin were found, which were identified by electron microscopy as mossy fiber boutons impinging on pyramidal neuron dendrites. Synaptic vesicles and endosomes in the mossy fiber boutons were labeled when incubated with exogenous horseradish peroxidase, indicating that they were competent for exo-endocytosis. Taken together, our data show that hippocampal granule neurons grown in dissociated primary cultures form mossy fiber boutons containing synaptophysin and synaptoporin at pyramidal cell dendrites. Since the composition and the characteristic morphology of mossy fiber boutons formed in vitro is the same as observed in vivo we conclude that their development follows an intrinsic program.

Assessing elderly acute care services: improving quality amid chaos.

Elderly service delivery within the medical-surgical division of a large midwestern tertiary care center was assessed to explore how to meet better the special needs and address the complex situations that older adults present. Twenty-seven nursing staff members working in the four medical-surgical units and the medical intensive care unit were interviewed using participant observation and unstructured interviewing methods as they delivered care to older adults. The following categories emerged from the qualitative data analysis: problems related to the care of older adults, causes of confusion, effective and potentially effective interventions for older patients, and staff educational needs. A major suggestion was to develop an interdisciplinary seniors team to provide consultation on issues related to older adults to nursing staff, medical staff, and other interdisciplinary staff involved in patient care. The team would evaluate the appropriateness of interventions, equipment, and personnel use related to older adults as well as identify and develop quality assurance activities to monitor and evaluate the care delivered to older adults.

[Differentiation of neurons of the cingulate region in explant culture]. / Differenzierung von Neuronen der Regio cingularis in der Explantatkultur.

The structural changes in explant-cultures of the cingulate region from the brains of 18 day old rat embryos were investigated during several cultivation periods by neurohistological light microscopical methods. The differentiation and the growth of neurons were observed in cultures stained by the method of Klüver-Barrera, and cut perpendicular to the coverslips during the period from the 1st up to the 20th day in vitro. As parameters for the growth of the cells the density of neurons and glial cells per culture area were estimated and the diameters of nuclei and pericarya were measured at different stages of culture. The following results could be obtained. 1. The immature cells differentiated up to the 20th day in vitro to neurons that could be devided into three groups due to histological characteristics: pyramidal cells, multiform neurons and a group of small cells with few cytoplasm. 2. From the 1st to the 20th day in vitro the density of neurons and glial cells markedly decreased. The number of neurons per unit area decreased to 59.7% during this period. However, the most rapid decrease in the number of neurons occurred from the 10th to the 20th day in vitro. 3. The measurements of the diameters showed an increase in both the diameters of nucleus and pericarya from the 1st to the 20th day in vitro. The enlargement of the diameters is especially striking from the 1st up to the 10th day in vitro. The results are discussed in comparison results of ontogenetic investigations in vivo.

Combined histochemical and x-ray microanalytical studies on the copper-accumulating granules in the mid-gut of larval Drosophila.

The copper-containing granules in the mid-gut epithelium of larval Drosophila melanogaster were examined for acid phosphatase by combined histochemistry and energy-dispersive, X-ray microanalysis. After incubation, many of the granules were shown to contain simultaneously copper and sulphur (which are normal constituents), and lead and phosphorus (which are the detectable elements of the reaction product). Earlier work has been consolidated and extended and the evidence that the granules are formed as cytolysosomes is reviewed.