Week-long Treatment Research Articles

Traditional Indigenous-Amazonian Therapy Involving Ceremonial Tobacco Drinking as Medicine: A Transdisciplinary Multi-Epistemic Observational Study.

Although the tobacco plant has been employed as a medicinal and sacred herb by Indigenous cultures across the Americas, its usage drastically changed after the 15th-century colonial arrival; its large-scale commodification and global marketing once brought to Europe lead to hedonic and addictive uses harmful to health. As a consequence, tobacco smoking is now one of the largest public health problems worldwide. However, in the Peruvian Amazon, a region of origin of tobacco species, Indigenous healers still know how to use the plant for therapeutic purposes. Due to a general disregard of Indigenous knowledge and stigma, these uses have however not so far been clinically investigated. We hence conducted for the first time a clinical field study assessing a sample of patients treated by a traditional healer specialized in tobacco in the Peruvian Amazon (observational design, pilot study, N = 27). The study was conducted within a transdisciplinary and multi-epistemic medical frame, in close partnership with an Amazonian healer. We used validated self-report scales to quantitatively assess mental health variables before and after the weeklong treatment, and mixed-methods to report experienced effects. Paired-samples t-tests comparing pre- and post-treatment scores revealed significant reductions in anxiety, depression, perceived stress, and general symptom indicators. Experienced effects included initial physical discomfort, followed by psychologically or existentially/spiritually significant insights. Our findings point to a sophisticated therapeutic approach based on Indigenous knowledge of tobacco applications, which should be further investigated. The study also contributes to the burgeoning scientific field on therapeutic uses of contentious psychoactive plants.

Individual response in body mass and basal metabolism to the risks of predation and starvation in passerines.

Wintering energy management in small passerines has focused on the adaptive regulation of the daily acquisition of energy reserves within a starvation-predation trade-off framework. However, the possibility that the energetic cost of living, i.e. basal metabolic rate (BMR), is being modulated as part of the management energy strategy has been largely neglected. Here, we addressed this possibility by experimentally exposing captive great tits (Parus major) during winter to two consecutive treatments of increased starvation and predation risk for each individual bird. Body mass and BMR were measured prior to and after each week-long treatment. We predicted that birds should be lighter but with a higher metabolic capacity (higher BMR) as a response to increased predation risk, and that birds should increase internal reserves while reducing their cost of living (lower BMR) when exposed to increased starvation risk. Wintering great tits kept a constant body mass independently of a week-long predation or starvation treatment. However, great tits reduced the cost of living (lower BMR) when exposed to the starvation treatment, while BMR remained unaffected by the predation treatment. Energy management in wintering small birds partly relies on BMR regulation, which challenges the current theoretical framework based on body mass regulation.

A flexible electronic strain sensor for the real-time monitoring of tumor regression.

Assessing the efficacy of cancer therapeutics in mouse models is a critical step in treatment development. However, low-resolution measurement tools and small sample sizes make determining drug efficacy in vivo a difficult and time-intensive task. Here, we present a commercially scalable wearable electronic strain sensor that automates the in vivo testing of cancer therapeutics by continuously monitoring the micrometer-scale progression or regression of subcutaneously implanted tumors at the minute time scale. In two in vivo cancer mouse models, our sensor discerned differences in tumor volume dynamics between drug- and vehicle-treated tumors within 5 hours following therapy initiation. These short-term regression measurements were validated through histology, and caliper and bioluminescence measurements taken over weeklong treatment periods demonstrated the correlation with longer-term treatment response. We anticipate that real-time tumor regression datasets could help expedite and automate the process of screening cancer therapies in vivo.

Interactive effects of acidification and copper exposure on the reproduction and metabolism of coral endosymbiont Cladocopium goreaui

Ocean acidification resulting from increased CO2 and pollution from land-sourced toxicants such as copper have been linked to coral cover declines in coastal reef ecosystems. The impacts of ocean acidification and copper pollution on corals have been intensively investigated, whereas research on their effects on coral endosymbiont Symbiodiniaceae is limited. In this study, reproduction, photosynthetic parameters, nutrient accumulation and metabolome of Symbiodiniaceae Cladocopium goreaui were investigated after a weeklong treatment with acute CO2-induced acidification and copper ion. Acidification promoted algal reproduction through increased nutrients assimilation, upregulated citrate cycle and biomolecular biosynthesis pathway, while copper exposure repressed algal reproduction through toxic effects. The combined acidification and copper exposure caused the same decline in algal reproduction as copper exposure alone, but the upregulation of pentose phosphate pathway and the downregulation of aromatic amino acid biosynthesis. These results suggest that copper pollution could override the positive effects of acidification on the symbiodiniacean reproduction.

Pharmacological Induction of NOXA Sensitizes High-Risk B Cell Acute Lymphoblastic Leukemia Cells to Venetoclax

Background: Venetoclax (VEN), a specific BCL2 inhibitor, exerts anti-leukemic effects in various high-risk (HR) B-ALL subtypes, such as ALL with mixed lineage leukemia (MLL) gene rearrangements (MLLr ALL) (PMID: 26711339), Philadelphia chromosome-positive (Ph+) (PMID 30546081) or hypodiploid B-ALL (PMID 30862722). Nevertheless, despite high rationale for targeting BCL2 in these subtypes of B-ALL, VEN monotherapy is not effective enough to completely eliminate leukemic cells. For this reason identification of other drugs that could sensitize leukemic cells to VEN may become beneficial treatment strategy in HR ALL. Previously, we showed that the enzymes of the thioredoxin system are upregulated in primary B-ALL cells and that auranofin (AUR), a thioredoxin reductase inhibitor, effectively kills leukemic cells in vitro and in vivo. Importantly, elements of the thioredoxin system are not only balancing redox homeostasis within the cells, but may also interact with other pathways, including anti-apoptotic signaling. Considering above, we hypothesized that AUR may potentiate VEN efficacy in HR B-ALL. Methods: To evaluate cytostatic/cytotoxic effects of VEN+AUR combination by MTT assay and propidium iodide (PI)-staining we used HR B-ALL cell lines, including SEM (MLLr ALL), BV-173 (Ph+ ALL) and NALM-16 (hypodiploid ALL). Patient derived xenograft cells (PDX) were generated through long-term propagation of primary B-ALL samples in immune-deficient NSG mice. Ex vivo drug testing in co-culture system was performed using primary bone marrow-derived mesenchymal stem cells (BM-MSC) and murine stromal OP9 cell line. NOXA genomic knockout (KO) in SEM cells was established by CRISPR/Cas9 system. Chromatin accessibility within PMAIP1 gene (encodes for NOXA) was detected using ATAC-seq. Results: We observed that AUR sensitizes HR B-ALL cell lines to VEN, as determined by MTT and PI-staining. Further, we mimicked the bone marrow support of stromal cells towards B-ALL and evaluated its impact on the response to VEN+AUR. For this reason we employed an ex vivo co-culture system of B-ALL PDX cells with primary BM-MSC or an OP9 cell line. In all tested PDX samples representing diagnostic/relapsed MLLr ALL (n=8), Ph+ ALL (n=2) and Ph-like ALL (n=2) we observed synergistic effect of this combination (Fig. 1A). Next, we determined the efficacy of VEN+AUR combination in vivo using a PDX model of MLLr B-ALL. We observed that administration of VEN+AUR diminished the progression of leukemia during a 3 week-long treatment more effectively than any single drug alone, which reflected in longer survival of NSG mice (Fig. 1B). Subsequently, we aimed to uncover the mechanism responsible for the synergistic action of VEN+AUR. In cells treated with both drugs we observed enhanced caspase activation and changes in the levels of BCL2 family proteins involved in apoptotic signaling. In particular, we found that AUR strongly upregulates a pro-apoptotic NOXA protein, both in HR B-ALL cell lines and in MLLr ALL PDX samples (Fig. 1C). To evaluate whether NOXA induction is functionally relevant for the cell death mediated by VEN+AUR, we generated SEM cells with a NOXA genomic KO. Lack of NOXA significantly abolished VEN-single agent as well as VEN+AUR combination cytotoxicity, demonstrating its dependence on NOXA expression (Fig. 1D). We then showed that NOXA is regulated at the transcriptional level, as co-treatment with AUR and the transcription inhibitor, actinomycin D, abolished AUR-mediated NOXA induction at mRNA and protein levels in SEM cells. Additionally, to test whether AUR-treatment itself provokes changes in chromatin accessibility within the NOXA encoding gene (PMAIP1) we performed ATAC-seq. We observed a clear increase in accessibility at PMAIP1 in response to AUR, which correlated with transcriptional induction of NOXA. Moreover, ChIP-qPCR revealed that increased ATAC peaks within PMAIP1 were associated with an increase in H3 lysine 27 acetylation (H3K27ac) - an epigenetic mark associated with open chromatin conformation. Conclusions: Our results demonstrate that FDA-approved drug, AUR, is a promising candidate to be used in combination with VEN for the therapy of HR B-ALL subtypes. Importantly, NOXA induction by AUR plays a central role in the VEN+AUR synergistic cytotoxicity. More studies elucidating the mechanism of NOXA upregulation by AUR are underway. Disclosures Milne: OxStem Oncology (OSO), a subsidiary company of OxStem Ltd.: Other: Founding shareholder .

Molecular changes associated with escitalopram response in a stress-based model of depression

Converging evidence points at hypothalamus-pituitary-adrenal (HPA) axis hyperactivity and neuroinflammation as important factors involved in the etiopathogenesis of major depressive disorder (MDD) and in therapeutic efficacy of antidepressants. In this study, we examined the molecular effects associated with a response to a week-long treatment with escitalopram in the chronic escape deficit (CED) model, a validated model of depression based on the induction of an escape deficit after exposure of rats to an unavoidable stress. We confirmed our previous result that a treatment with escitalopram (10mg/kg) was effective after 7days in reverting the stress-induced escape deficit in approximately 50% of the animals, separating responders from non-responders. Expression of markers of HPA axis functionality as well as several inflammatory mediators were evaluated in the hypothalamus, a key structure integrating signals from the neuro, immune, endocrine systems. In the hypothalamus of responder animals we observed a decrease in the expression of CRH and its receptors and an increase in GR protein in total and nuclear extracts; this effect was accompanied by a significant decrease in circulating corticosterone in the same cohort. Hypothalamic IL-1β and TNFα expression were increased in stressed animals, while CXCL2, IL-6, and ADAM17 mRNA levels were decreased in escitalopram treated rats regardless of the treatment response. These data suggest that efficacy of a one week treatment with escitalopram may be partially mediated by a decrease HPA axis activity, while in the hypothalamus the drug-induced effects on the expression of immune modulators did not correlate with the behavioural outcome.

Effects of orally administered enalapril on blood pressure and hemodynamic response to vasopressors during isoflurane anesthesia in healthy dogs

ObjectiveTo examine whether preanesthetic administration of enalapril, compared with placebo, results in a greater decline in blood pressure (BP) or decreased responsiveness of BP to isotonic fluids or vasopressors in healthy dogs during isoflurane anesthesia. Study designRandomized, experimental, placebo-controlled, blinded, crossover study. AnimalsTwelve healthy, female, purpose-bred beagles. MethodsDogs underwent the following week-long treatment protocols, each preceded by a 1 week washout period: oral placebo twice daily (PLA); oral enalapril, 0.5 mg kg−1 twice daily, with the 15th dose withheld on the day of anesthesia (ENA-W), and oral enalapril, 0.5 mg kg−1 twice daily, with the 15th dose administered 90 minutes prior to anesthetic induction (ENA). On day 8 of each treatment period, dogs were anesthetized in random order utilizing a standard protocol. Following stabilization at an end-tidal isoflurane concentration (Fe′Iso) of 1.3%, invasively measured systolic (SAP), diastolic (DAP) and mean (MAP) arterial blood pressure were continuously recorded via telemetry. Hypotension (SAP < 85 mmHg) was treated with the following sequential interventions: lactated Ringer's solution (LRS) bolus (10 mL kg−1); repeated LRS bolus; dopamine (7 μg kg−1 min−1); and dopamine (10 μg kg−1 min−1) first without and then with vasopressin (1 mU kg−1 hour−1). ResultsCompared with the PLA but not the ENA-W group, the ENA group had significantly lower average SAP, DAP and MAP at an Fe′Iso of 1.3%, spent more minutes in hypotension, and required a greater number of interventions to correct moderate-to-severe mean arterial hypotension. ConclusionsIn healthy dogs, enalapril administered 90 minutes prior to isoflurane anesthesia increases the degree of intra-anesthetic hypotension and the number of interventions required to correct moderate-to-severe hypotension. Clinical relevanceDogs receiving angiotensin-converting enzyme inhibitors on the day of anesthesia may exhibit clinically significant intra-anesthetic hypotension.

NWP06, an extended-release oral suspension of methylphenidate, improved attention-deficit/hyperactivity disorder symptoms compared with placebo in a laboratory classroom study.

The purpose of this study was to determine the efficacy of NWP06, a novel extended-release (ER) liquid formulation of methylphenidate (MPH), compared with placebo in the treatment of attention-deficit/hyperactivity disorder (ADHD) in children in a laboratory school. A total of 45 subjects ages 6-12 years were enrolled in this dose-optimized, randomized, double-blind, placebo-controlled, crossover laboratory school study. Following open-label dose optimization, subjects received 2 weeks of double-blind treatment (1 week of NWP06 and 1 week of placebo). The treatment sequence (NWP06/placebo or placebo/NWP06) was randomly assigned with the last day of each week-long treatment occurring on the laboratory school test day. Efficacy measures included Swanson, Kotkin, Agler, M-Flynn and Pelham (SKAMP) Rating Scale-Combined and Permanent Product Measure of Performance (PERMP) mathematics tests measured at pre-dose and at 0.75, 2, 4, 8, 10, and 12 hours post-dose on each laboratory classroom day. Safety assessments included physical examination, screening electrocardiogram (ECG), vital signs, clinical laboratory tests, adverse event measures, and assessment of suicidality with the Columbia Suicide Severity Rating Scale. NWP06 resulted in significant (p<0.0001) improvements in the SKAMP-Combined score at 4 hours post-dose (mean=7.12) as compared with placebo (mean=19.58) in the completers (n=39). Significant separation from placebo occurred at each time point tested (0.75, 2, 4, 8, 10, 12 hours), with onset of action of NWP06 at 45 minutes post-dose and duration of efficacy extending to 12 hours post-dose. Adverse events (AEs) and changes in vital signs following NWP06 treatment were generally mild and consistent with the known safety profile of MPH. The most common AEs in the open-label phase were decreased appetite (55.6%), upper abdominal pain (42.2%), affect lability (26.7%), initial insomnia (22.2%), insomnia (17.8%), and headache (17.8%). NWP06 treatment effectively reduced symptoms of ADHD in children beginning at 45 minutes and continuing for 12 hours post-dose. NWP06 was well tolerated. ClinicalTrials.gov Identifier: NCT00904670. http://www.clinicaltrials.gov/ct2/show/NCT00904670 .

Astragaloside IV inhibited the activity of CYP1A2 in liver microsomes and influenced theophylline pharmacokinetics in rats

With the growing popularity of herbal and natural medicinal products, attention has turned to possible interactions between these products and pharmaceutical drugs. In this study, we examined whether astragaloside IV (AGS-IV) could inhibit the activity of CYP1A2 in rat liver microsomes in vitro and in vivo. The effect of AGS-IV on CYP1A2 activity was investigated using probe substrates: phenacetin in vitro and theophylline in vivo. Phenacetin was incubated in rat liver microsomes with or without AGS-IV, and the mechanism, kinetics and type of inhibition were determined. The inhibitory effect of AGS-IV on CYP1A2 activity in rats was also determined using theophylline in vivo. The pharmacokinetics of theophylline were observed after a single or week-long treatment with AGS-IV. AGS-IV was found to be a competitive inhibitor with a K(i) value of 6.29 μM in vitro. In the multiple-pretreatment rat group, it was found to have a significantly higher area under the concentration-time curve (AUC) for theophylline, as well as a lower apparent oral total body clearance value (CL/F). In contrast, no significant difference in metabolism of theophylline was found for the single pretreatment group. These findings suggest that AGS-IV is a potent inhibitor of CYP1A2. This work offers a useful reference for the reasonable and safe use of clinically prescribed herbal or natural products to avoid unnecessary herb-drug interactions.

An Uncontrolled Examination of a 5-Day Intensive Treatment for Pediatric OCD

This study examined the feasibility of a 5-day intensive treatment for pediatric obsessive-compulsive disorder (OCD). Fifteen children with OCD received a week-long treatment based on exposure and response prevention (ERP). The intervention also emphasized teaching children and parents how to conduct ERP independently at home. All families completed the week-long treatment and symptoms improved significantly as measured by self- and parent-report forms, as well as the Children's Yale-Brown Obsessive-Compulsive Scale, F(2, 22) = 45.67, p < .05. Total CY-BOCS scores decreased significantly from pretreatment ( M = 28.00, SD = 4.24) to posttreatment [ M = 16.00, SD = 6.0, F(1, 11) = 34.38, p < .05] and from posttreatment to 5-month follow-up [ M = 11.5, SD = 7.3; F(1, 11) = 12.94, p < .05]. This level of improvement was consistent with other intensive treatments for pediatric OCD. The study suggests that the 5-day program is a promising treatment for children with OCD who do not have access to local providers.

Sustained appetite improvement in malnourished dialysis patients by daily ghrelin treatment

Malnutrition is a common complication in patients on dialysis and is strongly associated with poor prognosis. Effective therapy could substantially improve morbidity and mortality, but neither enteral nor parenteral supplementation provide long-term benefit because of the strong appetite suppression seen in such patients. We performed a double-blinded randomized crossover study of a week-long treatment with daily subcutaneous ghrelin, a gut hormone that regulates hunger through the hypothalamus, in a group of 12 malnourished dialysis patients. Ghrelin administration increased ghrelin levels in circulation, modestly reduced blood pressure for up to 2 h, and immediately and significantly increased appetite, with an increase in energy intake noted at the first study meal. Persistence of this effect throughout the week was confirmed with food diaries and final study meals. Energy expenditure, measured with free-living pulse and motion monitors, was unchanged by ghrelin. Our study shows that daily treatment with ghrelin achieves a sustained positive change in energy balance in malnourished dialysis patients. Direct manipulation of appetite with ghrelin or its analogs represents an attractive and promising therapeutic strategy for this difficult clinical problem.

Skeletal Muscle Insulin Resistance in Rats Fed a High Fat Diet and Treated with Acipimox

The mechanism by which a high fat diet causes insulin resistance is not yet understood. It has been proposed by some investigators that elevations in the circulating levels of free fatty acids are responsible for the development of insulin resistance. PURPOSE: The purpose of this study was to determine if the skeletal muscle insulin resistance induced by a high fat diet would persist in the context of a weeklong treatment to reduce plasma FFAs with acipimox. METHODS: Rats were fed standard chow or a high fat diet in which 50% of calories come from fat (lard and corn oil) for a period of 4 weeks. During the 5th week, a subset of the rats fed a high fat diet were given 2 doses (100mg/kg) per day of Acipimox, which inhibits lypolysis and reduces plasma FFA concentrations. Glucose uptake, Glucose tolerance, fat pad weights, and plasma FFA were measured to determine the metabolic profile and insulin resistance in these animals. RESULTS: the concentration of plasma FFA's were reduced in response to Acipimox treatment in high fat fed rats (0.75±0.08 and 0.38±0.07 mM in High fat fed and High fat+acipimox, respectively). Whole animal glucose tolerance was improved with acipimox treatment, and was not significantly different from that of the chow animals. Skeletal muscle insulin resistance was evident in the animals fed a high fat diet alone as well as rats that received acipimox. The insulin stimulated 2-Deoxyglucose uptake in the epitrochlearis muscle was 1.17±0.11, 0.82±0.11, and 0.68±0.10 μmol 2DG/ml/20min in chow, HF and Acip+HF groups respectively. High fat feeding caused a significant increase in total abdominal fat pad weights and acipimox treatment caused a further increase in fat pad mass (7.01±0.32, 12.80±0.71 and 15.75±0.43 gms fat in Chow, High Fat and High Fat+ acipimox, respectively). CONCLUSION: Lowering of plasma FFA with Acipimox improved overall insulin action, yet did not improve insulin resistance measured in epitrochlearis muscle.

Lamivudine treatment in maternally transmitted chronic hepatitis B virus infection patients

Lamivudine treatment in chronic carriers who acquired hepatitis B virus through maternal transmission were investigated. A total of 29 subjects (Male:Female, 24:5; mean age, 14.7 +/- 5.6 years) who were hepatitis B e antigen (HBeAg) seropositive for >6 months, alanine aminotransferase (ALT) was >1.3 times of upper limit of normal value, and receiving a 52 week-long treatment, received open-label lamivudine (3 mg/kg per day, maximum 100 mg/day). Another 29 subjects matched for gender, age, liver function, and HBeAg status followed up before the introduction of lamivudine served as the control group. The control group did not receive any treatment and were evaluated at week 52 after the onset of abnormal ALT. Mothers of all study subjects were hepatitis B surface antigen (HBsAg) carriers. A successful treatment response at week 52 was defined as: (i) undetectable hepatitis B virus DNA by real time polymerase chain reaction; (ii) normal ALT; and (iii) HBeAg/anti-HBe seroconversion. Lamivudine-resistant YMDD mutants were checked at week 52. The lamivudine group did not reach a better successful treatment response rate than the control group (17 vs 10%, P = 0.44), except in patients with a baseline ALT >5 times of the upper limit of normal value. YMDD mutants developed in 34% of patients in the lamivudine group. Lamivudine treatment is effective for maternally transmitted subjects with high ALT.

Multiple‐Dose FTY720: Tolerability, Pharmacokinetics, and Lymphocyte Responses in Healthy Subjects

FTY720 is a sphingosine-1-phosphate receptor agonist being developed as an immunomodulator for acute rejection prophylaxis after organ transplantation. This study was performed to characterize the pharmacokinetics of and lymphocyte response to multiple-dose FTY720. In this randomized, double-blind study, three groups of 20 healthy subjects each received either placebo, 1.25 mg/day FTY720, or 5 mg/day FTY720 for 7 consecutive days. FTY720 blood concentrations and lymphocyte counts were assessed over the weeklong treatment phase and over a month-long washout phase. The relationship between FTY720 blood concentrations and lymphocyte counts was explored by an inhibitory E(max) model. First-dose exposure was consistent with dose proportionality between the low- and high-dose groups. Blood levels accumulated fivefold over the treatment period. Exposure on day 7 was dose proportional for C(max) (5.0 +/- 1.0 vs. 18.2 +/- 4.1 ng/mL) and for AUC (109 +/- 24 vs. 399 +/- 85 ng.h/mL). Washout pharmacokinetics after the last dose indicated an elimination half-life averaging 8 days. Lymphocyte counts decreased by 80% in subjects receiving the lower dose to a nadir of 0.4 +/- 0.1 x 10(9)/L and by 88% in subjects receiving the upper dose to a nadir of 0.2 +/- 0.1 x 10(9)/L. Descriptive exposure-response modeling estimated that the lymphocyte response at 5 mg/day is near the maximal response achievable. By the end-of-study evaluation on day 35, lymphocyte counts had recovered to within 75% and 50% of baseline in the low- and high-dose groups, respectively. In summary, systemic exposure to FTY720 was consistent with dose-proportionality after both single- and multiple-dose administration. Total lymphocyte counts decreased from baseline by 80% and 88% at regimens of 1.25 and 5 mg/day, respectively. Exposure-response modeling provided evidence that 5 mg/day FTY720 resulted in a near-maximal dynamic effect of this drug on lymphocytes.

Effects of latanoprost and timolol-XE on hydrodynamics in the normal eye

PURPOSE: To compare the effects of latanoprost and timolol-XE on ocular pressure and perfusion in healthy adults, with respect to episcleral venous pressure. METHODS: A double-masked, placebo-controlled crossover study of weeklong bedtime treatment with one drop of drug, with placebo contralaterally, followed by a 3-week washout and alternate-drug/contralateral-placebo repeat. Intraocular pressure was measured by applanation and by pneumotonometry, providing pulsatile ocular circulatory estimates. Measurements of episcleral venous pressure were obtained (Friberg method). RESULTS: Twenty subjects participated (five men, 15 women; mean age, 39 years (range, 21 to 55 years); mean baseline intraocular pressure, 13.4 mm Hg). A greater decrease in intraocular pressure was seen among these subjects the morning after initiating treatment with latanoprost (−2.0 mm Hg; P < .0001) than with timolol-XE (−0.9 mm Hg; P = .051) (latanoprost versus timolol Δ P = .008). This ocular hypotensive effect remained significant that evening with latanoprost (−3.2 mm Hg; P < .0001) but not with timolol XE (−1.0 mm Hg; P = .2). By the morning of day 8, mean intraocular pressure remained 3.2 mm Hg below baseline with latanoprost and 2.3 mm Hg below baseline with timolol-XE ( P < .0001 for both drugs). Neither drug altered episcleral venous pressure. Among a subgroup of nine subjects with comparable intraocular pressure reductions with the two drugs, latanoprost treatment was associated with a 16.7% increase in mean pulsatile ocular blood flow ( P = .04) through the weeklong treatment interval, consistently higher than during timolol-XE treatment of the same subjects. CONCLUSION: Latanoprost caused an overnight decrease in intraocular pressure in normotensive normal eyes, and both drugs significantly reduced intraocular pressure within 1 week. Intraocular pressure remained higher than episcleral venous pressure throughout treatment with both drugs. Latanoprost was associated with enhanced pulsatile ocular perfusion not seen with timolol-XE treatment.

Quantitative Assessment of Angiogenesis and Tumor Vessel Architecture by Computer-Assisted Digital Image Analysis: Effects of VEGF–Toxin Conjugate on Tumor Microvessel Density

Tumor growth is angiogenesis dependent. As a consequence, strategies aimed at disrupting this mechanism are heavily investigated. Several angiogenesis assays are used to directly compare the efficacy of anti-angiogenic compounds. However, objective assessment of new vascular growth has been difficult to achieve. The aim of this study was to test and develop a computer-assisted image analysis method that would give an unbiased quantification of the microvessel density. Human tumors were grown in athymic mice and tumor biopsies were taken after a weeklong treatment with VEGF–toxin conjugate. Frozen tumor sections were prepared and stained with PE-conjugated anti-CD-31 antibodies and vessels were imaged with a fluorescence microscope. Vessel density was analyzed by quantifying PE-positive pixels per recorded field. In addition, images were further processed to investigate morphological differences by an automated binarization and skeletonization protocol. This procedure allowed the computer-assisted estimation of important angiogenic parameters such as total vessel number, length, and branch points. Based on these indices, differences in the angiogenic response between control tumors and those treated with VEGF–toxin conjugate were readily detected (P < 0.007 for all parameters). More importantly, computer-generated measurements correlated well with manual microvessel counts and showed significantly less variation. Our results suggest that computer-assisted image analysis represents a rapid, objective, and alternative method for the quantitative assessment of tumor angiogenesis and vessel architecture.

Food intake in diabetic rats: Relationship to metabolic effects of insulin treatment

Hyperphagic streptozotocin-diabetic rats were given week-long treatment with 0 (vehicle), 3, or 6 U/rat/day of regular insulin via a SC osmotic pump. Insulin reduced urinary glucose excretion and plasma glucose and increased body weight in a dose-related manner starting on the first day of treatment. Insulin treatment also increased carcass weight, carcass fat, and liver glycogen within 3 days. Food intake did not decrease until the fifth day of insulin treatment, and this change was unrelated to the amount of insulin administered. These results show that the effects of insulin on food intake and metabolism of diabetic rats can be dissociated with respect to both time course and dose of insulin. The findings indicate that hypoinsulinemia, glycosuria, body weight loss, and depletion of body fat and liver glycogen are symptoms of diabetes, not causes of diabetic hyperphagia.