Localized Sustained Release of Copper Enhances Antitumor Effects of Disulfiram in Head and Neck Cancer

Drug repurposing uses approved drugs as candidate anticancer therapeutics, harnesses previous research and development efforts, and benefits from available clinically suitable formulations and evidence of patient tolerability. In this work, the drug used clinically to treat chronic alcoholism, disulfiram (DSF), was studied for its antitumor efficacy in a copper-dependent manner. The combination of DSF and copper could achieve a tumor cell growth inhibition effect comparable to those of 5-fluorouracil and taxol on head and neck cancer cells. Both bulk dendrimer hydrogel and microsized dendrimer hydrogel particles were utilized for the localized sustained release of copper in the tumor site. The localized sustained release of copper facilitated the tumor inhibition effect following intratumoral injection in a mouse's head and neck cancer model.

Nano-in-Nano Dendrimer Gel Particles for Efficient Topical Delivery of Antiglaucoma Drugs into the Eye

Low bioavailability of topically applied drugs remains a significant challenge for long-term glaucoma therapy. To enhance drug delivery efficiency, we developed dendrimer gel particles that collectively exhibit structural benefits of dendrimer, hydrogel, and particles, using the inverse emulsion method coupled with the highly efficient aza-Michael addition reaction (IEaMA). This hierarchical approach would maximize the utility of the structural features of existing ocular drug delivery systems. We have tested the delivery efficiency and efficacy of two first-line antiglaucoma drugs, brimonidine tartrate (BT) and timolol maleate (TM), which were loaded into dendrimer gel particles of various sizes, i.e., nDHP (nano-in-nano dendrimer hydrogel particles, ~200 nm), μDHP3 (3 μm), and μDHP10 (9 μm). We found that nDHP was superior to μDHP3 and μDHP10 in terms of cytocompatibility, degradability, drug release kinetics, and corneal permeability. The nDHPs increased drug corneal permeability by 17-fold compared to plain drug solution and enabled zero-order prolonged drug release kinetics. The nDHP-based formulation demonstrated pronounced IOP-lowering effects in both single-dose test and 7-day chronic daily dosing test in both Brown Norway rats and glaucoma mice. Taken together, we have developed nano-in-nano dendrimer gel particles for precise dosing and enabling sustained and synergistic efficacy of antiglaucoma drugs, which could be clinically impactful for improving glaucoma treatment.

Over-Expression of Intestinal Alkaline Phosphatase Attenuates Atherosclerosis

[Figure: see text].

Polyamidoamine Dendrimer Grafted with an Acid-Responsive Charge-Reversal Layer for Improved Gene Delivery

We report on a heterogeneous dendrimer (G3-acetal-NH₂) derivative possessing an acid-responsive charge-reversal layer. The synthesis of G3-acetal-NH₂ starts with a polyamidoamine (PAMAM) dendrimer G3 core and follows the aza-Michael addition with N-(2-(1-(allyloxy)ethoxy)ethyl)acrylamide synthesized by us and the thiol-ene click chemistry with cysteamine hydrochloride in sequence. In a weakly acidic environment, the surface of this newly formed dendrimer can turn from amine-terminated to hydroxyl-terminated due to the cleavage of the acetal groups. This charge conversion from 34.3 ± 2.7 to 18.0 ± 0.3 mV in 24 h at pH 5.3 enables its capacity as a gene delivery vehicle. G3-acetal-NH₂ with a positively charged surface can condense pMAX GFP plasmid at similar weight ratios as native G4-NH₂ (above 2:1), allowing for its protected uptake into cells and endosomal escape. Meanwhile, in the endosome, the drop in vesicle pH cleaves the acetal bond, releasing the genetic payload and limiting its recondensation by the reduction in the dendrimer surface charge. When the vector/plasmid weight ratio was 2:1, G3-acetal-NH₂ improved transfection of pMAX GFP plasmid by 5-fold over native G4-NH₂ in NIH3T3 cells in terms of GFP protein expression. Taken together, we show that this surface charge conversion performance makes the synthesized heterogeneous dendrimer an improved vehicle for gene transfection.

Duplex of Polyamidoamine Dendrimer/Custom-Designed Nuclear-Localization Sequence Peptide for Enhanced Gene Delivery

Background: Dendrimers are an attractive alternative to viral vectors due to the low cost of production, larger genetic insert-carrying capacity, and added control over immune- and genotoxic complications through versatile functionalization. However, their transfection rates pale in comparison to their viral counterparts, resulting in widespread research efforts in the attempt to improve transfection efficiency. Materials and Methods: In this work, we designed a synthetic diblock nuclear-localization sequence peptide (NLS) (DDDDDDVKRKKKP) and complexed it with polyamidoamine (PAMAM) dendrimer G4 to form a duplex for gene delivery. We conducted transmission electron microscopy, gel mobility shift assay, and intracellular trafficking studies. We also assessed its transfection efficiency for the delivery of a green fluorescent protein-encoding plasmid (pGFP) to NIH3T3 cells. Results: PAMAM dendrimer G4, NLS, and plasmid DNA can form a stable three-part polyplex and gain enhanced entry into the nucleus. We found transfection efficiency, in large part, depends on the ratio of G4:NLS:plasmid. The triplex prepared at the ratio of 1:60:1 for G4:NLS:pGFP has been shown to be more significantly efficient in transfecting cells than the control group (G4/pGFP, 0.5:1). Conclusions: This new diblock NLS peptide can facilely complex with dendrimers to improve dendrimer-based gene transfection. It can also complex with other polycationic polymers to produce more potent nonviral duplex gene delivery vehicles.

Injectable Multicomponent Biomimetic Gel Composed of Inter-Crosslinked Dendrimeric and Mesoporous Silica Nanoparticles Exhibits Highly Tunable Elasticity and Dual Drug Release Capacity

There is a growing need for cartilage defect grafts that are structurally adaptable to possess multifaceted functions to promote bone regeneration, sustain medication efficacy, and preferably remain injectable but solidify quickly upon injection. In this work, we developed an injectable multicomponent biomimetic gel (MBG) by integrating polyamidoamine dendrimer G3 (G3), mesoporous silica nanoparticles (MSNs), and dendrimer-templated silver nanoparticles (G3-Ag) into a well-defined cross-linked network. MBGs composed of one particulate component (G3 alone), i.e., MBG-1, two particulate components (G3 and MSN-NH2), i.e., MBG-2, and three particulate components (G3, MSN-NH2, and G3-Ag), i.e., MBG-3, were prepared by inter-cross-linking dendrimeric and mesoporous silica nanoparticles with poly(ethylene glycol) diglycidyl ether (PEG-DGE, Mn = 2000 g/mol) via the facile amine-epoxy click reaction. The water-soluble antibiotic isoniazid was loaded to the cross-linked PEG network, whereas the hydrophobic antibiotic rifampicin was encapsulated into mesoporous MSNs. Our studies revealed that elasticity and mechanical strengths could be modulated and enhanced significantly with the inclusion of MSNs and silver nanoparticles. Isoniazid was released rapidly while rifampicin was released over an extended period of time. In addition, MBGs showed injectability, high swelling capacity, structural stability, and cytocompatibility. Taken together, MBGs have shown structural features that allow for the development of injectable gel grafts with the ability to promote cartilage defect repair and offer antibiotic medication benefits.

Hydrogel-based ocular drug delivery systems: Emerging fabrication strategies, applications, and bench-to-bedside manufacturing considerations

The physiological barriers of the eye pose challenges to the delivery of the array of therapeutics for ocular diseases. Hydrogels have been widely explored for medical applications and introduce possible solutions to overcoming the medication challenges of the ocular environment. While the innovations in drug encapsulation and release mechanisms, biocompatibility, and treatment duration have become highly sophisticated, the challenge of widespread application of hydrogel formulations in the clinic is still apparent. This article reviews the latest hydrogel formulations and their associated chemistries for use in ocular therapies, spanning from external anterior to internal posterior regions of the eye in order to evaluate the state of recent research. This article discusses the utility of hydrogels in soft contact lens, wound dressings, intraocular lens, vitreous substitutes, vitreous drug release hydrogels, and cell-based therapies for regeneration. Additional focus is placed on the pre-formulation, formulation, and manufacturing considerations of the hydrogels based on individual components (polymer chains, linkers, and therapeutics), final hydrogel product, and required preparations for clinical/commercial applications, respectively.

Drug-Conjugated Dendrimer Hydrogel Enables Sustained Drug Release via a Self-Cleaving Mechanism

In this study, the anticancer drug, camptothecin (CPT), was covalently grafted onto polyamidoamine (PAMAM) dendrimer surface and then reacted with polyethylene glycol diacrylate (PEG-DA) to form dendrimer hydrogel (DH-G3-CPT) with low cross-linking density. In this novel drug delivery system, CPT was cleaved from dendrimer via the ammonolysis of ester bonds and then diffused out of the hydrogel network, thus leading to significantly prolonged drug release. The self-cleaving release kinetics of camptothecin can be further tuned by pH. This DH-G3-CPT drug delivery system has both injectability and sustained drug release. It showed an excellent tumor inhibition effect following intratumoral injection in a head and neck cancer model of mouse.

Polyamidoamine Dendrimer Microgels: Hierarchical Arrangement of Dendrimers into Micrometer Domains with Expanded Structural Features for Programmable Drug Delivery and Release

In this paper, we report on the fabrication of micron-sized dendrimer hydrogels (μDHs) using the water-in-oil (w/o) inverse microemulsion method coupled with the highly efficient aza-Michael addition. EDA core polyamidoamine (PAMAM) dendrimer G5 (10 w%) and polyethylene glycol diacrylate (PEG-DA, M n = 575 g/mol) (the molar ratio of amine/acrylate = 1/1) were dissolved in the water phase and added to hexane in the presence of surfactants span 80/tween 80 (5/1, w/w) (volume ratio of hexane to surfactants: 70:1) to form w/o microemulsions, in which PAMAM G5 cross-links with PEG-DA via the aza-Michael addition reaction. The resulting microgels are within 3-5 μm with relatively narrow size distribution. μDHs are pH-responsive degradable. They show good cytocompatibility and do not cause acute toxicity in vivo. Furthermore, they can realize a high loading of the hydrophobic drug CPT and enter the cells in the form of particles. The CPT and CPT/dendrimer complex can be slowly released following the zero-order release kinetics. Taken together, μDHs possessing hierarchically ordered dendrimers in micron domains represent a new class of microparticles with expanded structural features for programmable drug delivery and release.

Synthesis and Application of Injectable Bioorthogonal Dendrimer Hydrogels for Local Drug Delivery

We developed novel dendrimer hydrogels (DH)s on the basis of bioorthogonal chemistry, in which polyamidoamine (PAMAM) dendrimer generation 4.0 (G4) functionalized with strained alkyne dibenzocyclooctyne (DBCO) via PEG spacer (M_n = 2,000 g/mol) underwent strain-promoted azide-alkyne cycloaddition (SPAAC) with polyethylene glycol bisazide (PEG-BA) (M_n= 20,000 g/mol) to generate a dendrimer-PEG cross-linked network. This platform offers a high degree of functionality and modularity. A wide range of structural parameters including dendrimer generation, degree of PEGylation, loading density of clickable DBCO groups, PEG-BA chain length as well as the ratio of clickable dendrimer to PEG-BA and their concentrations can be readily manipulated to tune chemical and physical properties of DHs. We used this platform to prepare an injectable liquid DH. This bioorthogonal DH exhibited high cytocompatibility and enabled sustained release of the anticancer drug 5-fluorouracil (5-FU). Following intratumoral injection, the DH/5-FU formulation significantly suppressed tumor growth and improved survival of HN12 tumor-bearing mice by promoting tumor cell death as well as by reducing tumor cell proliferation and angiogenesis.

Sample Confirmation Testing: A Short Tandem Repeat-Based Quality Assurance and Quality Control Procedure for the eyeGENE Biorepository

Quality assurance and quality control (QA/QC) procedures are vital to good biorepository management. The National Eye Institute (NEI) core CLIA-certified laboratory of the eyeGENE(®) Network receives blood from individuals with inherited eye conditions and isolates DNA for clinical genetic diagnostic testing and research. Clinical genetic test results are returned to the affected individuals, making it imperative that sample integrity is preserved throughout laboratory processing. A clinically validated, short tandem repeat (STR)-based approach, termed Sample Confirmation Testing (SCT), was developed to ensure that no significant laboratory errors occurred during processing. SCT uses modified protocols from commercial kits to create and compare STR profiles for each participant's original blood and derived DNA. This QA/QC procedure has been performed on 47% of the more than 6000 participants in the eyeGENE Biorepository and has identified significant laboratory errors in 0.4% of samples tested. SCT improves the quality of the data returned to affected individuals and the data distributed to researchers using eyeGENE samples by ensuring the integrity of the samples and aiding in curation of the biorepository. This approach serves as a model for other repositories to improve sample quality and management procedures.

A portable system for the assessment of neuromuscular diseases with electrical impedance myography

PRIMARY OBJECTIVE

To create a system for the acquisition of multi-angle, multifrequency muscle impedance data.

RESEARCH DESIGN

Device development and preliminary testing.

METHODS AND PROCEDURES

The system presented here employs an interrogating signal composed of multiple tones with frequencies between 10 kHz and 300 kHz. The use of a composite signal makes possible measurement of impedance at multiple frequencies simultaneously. In addition, this system takes impedance measurements at multiple orientations with respect to the muscle fibres by means of an electronically reconfigurable electrode array. The required measurement time is reduced by taking advantage of muscle's linearity with respect to the flow of electrical current.

MAIN OUTCOMES AND RESULTS

The system was tested in normal subjects, a patient with amyotrophic lateral sclerosis, and one with inclusion body myositis; unique impedance signatures were identified the two patients.

CONCLUSIONS

Early data suggest that this system is capable of high-quality data collection and may detect changes in neuromuscular disease; study of additional normal subjects and patients with a variety of neuromuscular diseases is warranted.

The ovariectomized sheep as a model for human bone loss

The aim of this study was to determine the effects of ovariectomy on the trabeculae of ovine iliac bone, with a view to the further development of a model for human osteoporosis. Seven ovariectomized (OVX) and five control Dorset ewes were observed for one year. Iliac crest bone samples were obtained at the time of ovariectomy ("time 0") and again when the animals were killed 12 months later. At "time 0" and at 3-month intervals thereafter samples of blood and urine were collected for the assay of serum 17beta-oestradiol and osteocalcin (OC) and urinary deoxypyridinium (D-PYR). One year after ovariectomy, trabecular bone volume and thickness were reduced (P<0.05) and trabecular separation was increased (P<0.05) as compared with the controls. In OVX sheep, serum 17beta-oestradiol concentrations were significantly lower at the end of the experiment than at "time 0", while serum OC and urinary D-PYR concentrations were significantly higher (P<0.001). The results suggest that the OVX sheep is a valid model for changes in trabecular bone architecture associated with oestrogen deficiency, especially in women experiencing early menopause.

Effect of estrogen deficiency on skeletal and alveolar bone density in sheep

BACKGROUND

This study provides a longitudinal assessment of changes in alveolar and skeletal bone mineral density (BMD) in ovariectomized animals.

METHODS

Following ovariectomy (OVX) (n = 6) or sham-operation (n = 6) intraoral radiographs were made at 4-month intervals and serum 17-beta-estradiol, osteocalcin, and interleukin (IL)-6, urinary deoxypyridinium, and salivary IL-6, deoxypyridinium, and osteocalcin concentrations were evaluated. Twelve months after surgery, animals were sacrificed and the mandible and radius/ulna removed. Bones were sectioned and radiographed. Mean BMD and cortical thicknesses were calculated from each region.

RESULTS

OVX animals had a progressive decrease in serum 17-beta-estradiol, increased serum osteocalcin and IL-6, urinary deoxypyridinium and salivary IL-6, osteocalcin and deoxypyridinium (P < 0.001), suggesting that they were becoming osteoporotic. The BMD of the radius/ulna and mandibular alveolar bone was significantly reduced in OVX animals (P < 0.05 and P < 0.001, respectively). Reduced alveolar bone BMD became evident in OVX animals 6 months after surgery and became more severe during the subsequent 6 months. Alveolar crestal height was also significantly reduced in OVX animals (P < 0.001). These biochemical and density changes preceded a significant reduction in serum 17-beta-estradiol, which occurred between 4 and 8 months following surgery.

CONCLUSIONS

Serial measurements of alveolar BMD predicts loss of skeletal BMD in OVX sheep. Changes in alveolar BMD precede estrogen deficiency, suggesting that early signs of reduced BMD may be detected in peri-menopausal women. The presence of biomarkers of bone metabolism within saliva and their correlation with reduced BMD suggests that saliva could be used as an adjunct screening method for assessment of skeletal bone density.

Preliminary evaluation of a new dental implant design in canine models

Problems with crestal bone resorption and bone adaptation to dental implants in compromised and weak bone present clinical challenges due to insufficient bone volume. Mathematical models have shown that a new, square-thread, dental implant design increases functional surface area and reduces shear loading at the implant interface. The aim of this investigation was to evaluate the ability of bone to grow between the threads of the new implant and its general biocompatibility in a canine model. Test implants were placed in the mandibles of four beagle dogs after posterior partial edentulism. Three months after implantation, the animals received independent fixed partial dentures, were followed for an additional 6 months, and then euthanized for histological analyses. Analyses revealed that bone grew between the threads and closely apposed the new implant design. Histological observations also revealed that the inferior aspect of the test implant threads were apposed by more bone than the coronal aspect, suggesting a biological advantage for the compressive load transfer mechanism of the new implant design. The results of this study revealed that the new implant design became osseointegrated with bone growing between the threads of the device.

Mini review of canine stifle joint anatomy

The stifle is a complex, condylar, synovial joint that allows motion in three planes. The complexity of the normal motion is directly related to the structure and functions of the anatomical components that form the joint. Alteration in any one of these components often leads to dysfunction as well as an increased risk of damage to other structures in the joint. Thus understanding of the normal anatomy and function of each stifle joint component is essential for proper diagnosis and treatment of any stifle joint injury. This review highlights the basic anatomy and function of the stifle joint components.

MRI screening for acoustic neuroma: a comparison of fast spin echo and contrast enhanced imaging in 1233 patients

Gadolinium enhanced MRI is the gold standard investigation for the detection of acoustic neuroma. Non-contrast MRI sequences have been suggested as an alternative for screening examinations. In order to determine the utility of fast spin echo imaging, both gadolinium enhanced T1 weighted images and fast spin echo T2 weighted images were acquired in 1233 consecutive patients referred for exclusion of acoustic neuroma. Two radiologists independently recorded their findings. Fast spin echo T2 weighted images were evaluated with respect to the visibility of nerves within the internal auditory canals and allocated a confidence score for the presence or absence of acoustic neuroma. 33 acoustic neuromas were identified. Only 56% were confidently identified on fast spin echo T2 weighted images alone; gadolinium enhanced T1 weighted images were required to confirm the diagnosis in 44% of the cases, including 9 of the 10 intracanalicular tumours. However, when identification of two normal intracanalicular nerves is employed as the criterion of normality, the single fast spin echo T2 weighted sequence excluded acoustic neuroma in 59% of this screened population. It is concluded that an imaging strategy intended to identify small intracanalicular acoustic neuromas cannot rely on fast spin echo T2 weighted imaging alone. Gadolinium enhanced T1 weighted imaging could be restricted to patients where fast spin echo images do not exclude acoustic neuroma but this strategy requires continuous supervision by an experienced radiologist. In most practices the screening examination should continue to include a gadolinium enhanced sequence in order to optimize the detection of small acoustic neuromas.

A swine model for the evaluation of efficacy of anti-microbial catheter coatings

A swine model was developed to investigate the efficacy of percutaneous venous catheters with anti-microbial coatings. The catheters used in the study consisted of silver-coated and uncoated catheters, both designed for percutaneous venous access. Five commercial pigs were each implanted with three venous catheters and followed for a period of 90 days. Two of the three catheters were coated and one was uncoated. To evaluate the percutaneous aspects of the catheters in the model, two venous access catheters were implanted percutaneously, parallel to the dorsal midline. These catheters were just caudal to the region that is dorsal to the scapula in each animal. In each case, the catheter to the left of the dorsal midline was silver-coated while the catheter to the right of the dorsal midline was uncoated. A silver-coated catheter was also implanted in the left external jugular vein of each animal and buried subcutaneously in order to evaluate the elution of the coating through the body under venous contact. Over the 90 day period, the concentration of silver in the blood rose to a mean peak level of 23.2 ppb following implantation of the catheters and then decreased after the second post-surgery week. The histological evaluation and macroscopic inspection at necropsy revealed minimal tissue response to both coated and uncoated materials. Data on bacterial growth indicated that bacteria were present at the terminal subcutaneous end of two of the uncoated percutaneous catheters. Based upon serum silver levels, exudate formation, histological examination, and bacterial growth information, the swine model was deemed to be suitable for testing the efficacy of catheters containing anti-microbial coatings.

Alveolar bone loss one year following ovariectomy in sheep

There is little information concerning the incidence of alveolar bone loss in estrogen-deficient women. Ovariectomized sheep are valid models for study of the effects of estrogen deficiency on bone metabolism. The objective of this study was to compare alveolar bone loss in control (C) and ovariectomized sheep (OVX) at 3 and 12 months following surgery. OVX animals had decreased serum levels of 17-beta-estradiol and increased serum levels of osteocalcin, IL-6, and urinary levels of deoxypyridinoline which, taken together, suggest development of osteoporosis. The mean probing depths and percentage of sites with pocket depths 4 to 6 mm and > 6 mm were significantly greater in OVX than C at each time period and in OVX were significantly greater at 12 months that at 3 months. Gingival tissue interleukin-6 (IL-6) levels (but not the number of IL-6(+) cells) were elevated adjacent to deep periodontal pockets; however, there was no significant elevation of levels of the proinflammatory cytokines IL-1 beta and IL-8 within gingiva. Taken together, the data suggest a systemic contribution for progression of periodontal disease associated with estrogen deficiency. This may involve upregulation of systemic IL-6 synthesis and transfer to gingiva in serum, resulting in enhanced IL-6 accumulation within the gingival tissues or reduced bone density allowing for a greater amount of alveolar bone loss.

DNA haplotypes of the complement C6 and C7 genes associated with deficiencies of the seventh component; and a new DNA polymorphism in C7 exon 13

Eight common DNA polymorphisms have been described for the linked C6 and C7 genes. We now describe a ninth polymorphism in C7 exon 13 which is located in a tight cluster with two previously reported markers. We have used all these markers to investigate the heterogeneity of C7 deficiency. Five of the nine C7 deficient probands (resident in Ireland, South Africa, Russia and Israel) are heterozygous for C6/C7 haplotypes. Seven different C7 deficient haplotypes were found for C7 markers alone, but all the four Israelis share one and three out of four Irish haplotypes share another. The markers appear to be a good guide to the heterogeneity of C7 deficiency and have been useful in choosing homozygous subjects for the investigation of molecular defects.

A natural mutant of plasmid RP4 that confers phage resistance and reduced conjugative transfer

A natural isolate of RP4 (PRC#116) acquired from the Stanford University Plasmid Reference Center differed from the wild-type Incompatibility Group P plasmid in several respects. Cells of Escherichia coli harboring PRC#116 were resistant to the IncP pili-specific bacteriophage PRD1 and GU5, and transferred this plasmid at a lower efficiency than the wild-type RP4. Phage sensitivity was restored, and transfer considerably improved in PRC#116+ bacteria transformed with plasmid constructs containing the origin of transfer (oriT region) of RP4. Mutant RP4 plasmids equivalent to PRC#116 were selected at a high frequency from an RP4+ E. coli population infected with PRD1 indicating that this RP4 variant may be the product of a very common mutation of the wild-type plasmid.

Differential cardiovascular effects of propranolol, atenolol, and pindolol measured by impedance cardiography

We have evaluated Sramek's method of impedance cardiography as a non-invasive way of detecting the cardiovascular effects of drugs. We made cardiovascular measurements using the method during passive tilting and exercise 2 h after the oral administration of atenolol (50 and 100 mg), propranolol (40 and 80 mg), pindolol (5 and 10 mg), and placebo in seven separate studies involving eight healthy male volunteers. Equivalent doses of the pure antagonists atenolol (beta 1) and propranolol (beta 1, beta 2) produced similar reductions in heart rate, systolic blood pressure, and cardiac index, and increases in stroke volume and total peripheral resistance, particularly during exercise. In contrast the partial agonist pindolol produced increases in heart rate and cardiac index, and reductions in peripheral resistance at rest. During passive tilting and exercise pindolol reduced heart rate, but cardiac output and total peripheral resistance were unchanged except at the highest levels of exercise. The similar cardiovascular effects of atenolol and propranolol, but differing effects of pindolol, are consistent with reports using other methods of measurement. This suggests that impedance cardiography may have a place in the non-invasive assessment of the cardiovascular effects of drugs.

The hygienic aspects of wastewater reuse

Historically drinking water contaminated with wastewater discharged from nearby communities has been a major public health problem whose solution was directed towards the treatment of drinking water rather than of the source of contamination. The increased need for deliberate wastewater reuse has stimulated greater interest in the ability of wastewater treatment processes to produce a product in which the risk of infection, upon reuse, is reduced to an acceptable level. A brief overview of the disease agents involved, human dose-response considerations, microbial standards, and treatment plant reliability is presented. Selected experiences with the question as to how our terrestrial experience can be applicable to advanced life support systems is addressed.

A study of immune responses to myelin and cardiolipin in patients with systemic lupus erythematosus (SLE)

Sera from 39 patients with SLE, 20 patients with cerebrovascular disease with no evidence of SLE, and 20 normal controls were tested for antibodies to cardiolipin (CL), brain total upper (UPG) and lower phase (LPG) glycolipids, myelin basic protein (MBP), myelin, and single strand DNA (ssDNA) by ELISA. Binding to the glycolipids and MBP was negative or negligible in all the groups, but significant binding was observed against CL, myelin and ssDNA in some of the SLE patients. Many sera from SLE patients with cerebral disorders and high CL binding also demonstrated high binding to myelin. These sera also labelled cell surface antigens on neonatal mouse neurons and astrocytes by immunofluorescence in tissue culture. A correlation was found to exist between anti-CL and antimyelin antibodies in SLE patients with cerebral lesions, but not between anti-ssDNA and anti-CL antibodies. As much as 80-90% of the specific activity of these antibodies could be absorbed out by the relevant antigens but only partially by the other antigens. In the control groups binding was low and no specific absorption could be demonstrated.

Deficiency of the seventh component of complement. A case report

Deficiency of the 7th component of the complement cascade was diagnosed in a white male with recurrent meningococcal infections. This deficiency has not previously been reported in South Africa.

Prophylaxis against Neisseria meningitidis infections and antibody responses in patients with deficiency of the sixth component of complement

Forty South African patients with homozygous deficiency of the sixth component of complement (C6) have been identified in an area where group B meningococcal meningitis is endemic; 22 of the 24 proband cases presented with recurrent meningococcal meningitis. In a 2- to 4-year prospective study, patients with recurrent infections who received monthly prophylactic long-acting penicillin were significantly protected from subsequent neisserial infection compared with those who did not receive penicillin (P = .02, Fisher's exact test). Heterogeneous susceptibility to neisserial infection was confirmed by following C6-deficient patients who presented with one or no Neisseria meningitidis infections. These patients, on no prophylaxis, had significantly fewer infections (P = .004) than did patients who presented with recurrent disease. Functional C6 activity was restored by transfusion of fresh frozen plasma in a C6-deficient patient resistant to conventional antibiotic treatment. Antibody levels to the serotype 2 outer membrane proteins were significantly elevated in C6-deficient patients compared with control groups (P = .001).

Electroconvulsive therapy--induced hemodynamic changes unmask unsuspected coronary artery disease

Electroconvulsive therapy (ECT) is known to produce increases in heart rate and blood pressure during seizure activity due to sympathetic stimulation and systemic catecholamine surges. These intense, brief hemodynamic changes can adversely affect myocardial oxygen supply and demand. In patients with compromised myocardial circulation, ECT can unmask undiagnosed cardiac disease. In this case report, ECT was performed on a 64-year-old white male with negative cardiac history. The patient awakened complaining of chest pain and ST wave depression was noted on the electrocardiogram. Cardiology consultation and cardiac catheterization were followed by coronary artery bypass surgery for significant coronary artery stenosis prior to resumption of ECT treatments. The physiological changes that occur during ECT are discussed, as well as pitfalls in evaluation of these patients for ECT treatment.

The relationship of anticardiolipin antibodies to disease activity in systemic lupus erythematosus

Sera from 124 blood donors, 60 rheumatoid arthritis (RA) and 57 SLE patients were measured for anticardiolipin antibodies by ELISA. Significantly raised IgG (aCLG) and IgM (aCLM) anticardiolipin antibody levels were found in RA and SLE (p less than 0.0005). However, in SLE both aCLG and aCLM levels were significantly higher than in RA (p less than 0.0025). We then conducted a transectional study to evaluate aCL levels and disease activity in SLE. There was a good positive predictive value (70%) between aCL and overall disease activity, but not for individual systems. A strong association between aCL and renal involvement irrespective of activity was also found (80%). Nine SLE patients fulfilled both the clinical and serological criteria for the antiphospholipid syndrome (APS) and a further 18 patients fulfilled the serological criteria for APS. Results indicate that aCL levels are of value in predicting overall disease activity in SLE and in monitoring those patients who fulfil or partially fulfil the criteria for APS.

Observations on the repair of distal radial osteotomies in the dog by double hook plates

Distal radial osteotomies in the dog repaired with a double hook plate achieved early return to full function. All dogs in this study reached and maintained the desired clinical evaluation score of grade four by the third postoperative week. The average loss of total range of carpal joint motion was 36 degrees. The double hook plate provides stable fixation and can be applied with three point fixation to a bone segment as short as 12 mm.

Anti-cardiolipin antibodies in ischaemic heart disease

IgG and IgM anti-cardiolipin antibodies (ACA) were assayed by an ELISA technique in 86 patients with ischaemic heart disease (IHD) and compared to 124 healthy controls and to 62 patients with rheumatoid arthritis (RA) and 20 with tuberculosis (TB). IgG ACA levels in IHD, RA and TB were comparable and significantly higher than in controls (P less than 0.0001). IgM ACA was significantly higher in IHD and RA than controls (P less than 0.0001) but not TB (P = 0.045). The number of IHD patients with raised ACA (IgG and/or IgM) was significantly greater than in RA or TB. (chi 2 = 30.77, P less than 0.0001). ACA were raised in 80.2% IHD patients on one or more occasions during a 1-11 day (mean 4.7) hospital admission. There was no difference in either ACA levels or in the frequency of ACA elevation in patients with stable or unstable angina pectoris or myocardial infarction. We conclude that there is a strong association between IHD and ACA with potentially important therapeutic implications.

Blood supply to the periosteum of the canine tibia

A study was undertaken to determine which arteries supply the periosteum of the normal adult canine tibia. The vessels were found to arise from locations distinct from the muscular vascularization. The venous drainage of the tibial periosteum had a satellite relationship with the arteries. On the surface of the periosteum, the vessels formed rectangular patterns. All surfaces of the distal end of the tibia seemed to have less distinct anastomoses of the transverse periosteal twigs, compared with the proximal end of the tibia.

Deficiency of the sixth component of complement and susceptibility to Neisseria meningitidis infections: studies in 10 families and five isolated cases

Complement component C6 deficiency (C6D) was diagnosed in 15 patients who presented, independently, with recurrent meningococcal infection. This condition is thus not particularly rare in the Cape. Ten of the patients belonged to multiplex families, and family studies led to the diagnosis of another 12 C6D cases among the siblings. Segregation analysis showed that C6D occurred more frequently among the siblings of affected individuals than would be expected for co-dominant inheritance. The possible reasons for this are discussed. We also observed that the 12 non-proband C6D siblings included only four with a history suggestive of meningococcal infection, and thus C6D individuals apparently differ in susceptibility to Neisseria meningitidis infection. We confirmed previous observations that primary infection occurs later in C6D individuals than amongst susceptible complement-sufficient individuals. Among 123 patients presenting with primary meningitis, one case of C6D was diagnosed. The data show that C6D is an important factor associated with susceptibility to meningococcal infection in the Cape.

Enzyme-linked immunosorbent assay for the detection of mycobacterial antigens in the cerebrospinal fluid in tuberculous meningitis

Fifty-three cerebrospinal fluid specimens from meningitis patients were investigated by enzyme-linked immunosorbent assay for detection of mycobacterial antigens. After heating at 56 degrees C for 1 hour to eliminate nonspecific interference, all 22 tuberculous meningitis (TBM) specimens had an optical density of greater than 0.05 (sensitivity 100%). Six out of 31 non-TBM cases gave false-positive results (specificity 81%).

Aetiology of pulmonary dysfunction in total hip replacement operations. The influence of nifedipine on the factors involved

Patients undergoing total hip replacement surgery who developed pulmonary dysfunction (PD) demonstrated evidence of complement activation and increased thromboxane A2 (TXA2) synthesis. In a double-blind study nifedipine (Adalat; Bayer-Miles) was shown to inhibit complement activation and TXA2 synthesis and thus appears to offer protection against PD.

Extracorporeal bypass of the right ventricle and pulmonary trunk using autogenous lungs for oxygenation in the dog

A technique for right heart bypass using autogenous lungs for oxygenation was evaluated. Venous blood was collected by a catheter placed in the right atrium and caudal vena cava. The blood then passed through the extracorporeal unit and was pumped into the pulmonary circulation. This technique allowed direct surgical exposure of the conus arteriosus, pulmonary valve, and pulmonary trunk. The surgical procedure, plasma hemoglobin levels, platelet and leukocyte counts, arterial blood gas, serum proteins, electrocardiogram, and postmortem findings were evaluated. Although there were significant alterations in many of these parameters, seven of eight dogs were successfully perfused and recovered rapidly from the surgery. One dog died of complications arising from inadequate venous return before bypass was established. On the first postoperative day, the survivors were ambulatory, eating, and having normal bowel function. Right heart bypass may be an effective method to approach lesions involving the conus arteriosus, pulmonary valve, and pulmonary trunk.

Serum immunoglobulin and complement values in onyalai. Comparison with black, San and white inhabitants of Kavango, SWA/Namibia

The hypothesis that onyalai results from a polyclonal immune response and that complement activation occurs in its active phase was investigated. Serum immunoglobulins IgA, IgG and IgM and complement fractions C3 and C4 were measured in 21 black onyalai patients and 44 of their close relatives, 37 healthy black schoolchildren, 42 Barakwenga San, 10 Kung San and 18 whites in Kavango. An additional 4 patients with onyalai were investigated after splenectomy. Total complement level, circulating immune complexes and antinuclear antibodies were measured in an additional 6 patients with active onyalai. The results did not support the hypothesis.

The effect of water activity on Legionella spp. growth and survival

Growth and survival of Legionella spp. at various water activity (aw) levels were determined. Compared with Escherichia coli, the growth of Legionella spp. was limited to a high aw environment (greater than or equal to 0.98).

Continuous caudal epidural anesthesia in the horse

A technique for continuous caudal epidural anesthesia in the horse was developed in trials involving 8 healthy adult horses. The injection site was the first intercaudal (intercoccygeal) space. A Huber point directional needle (Tuohy or Hustead) with a stylet was preplaced into the epidural space, used as a guide for an epidural catheter, and then removed, leaving the catheter in situ in the epidural space. A 2% solution of lidocaine hydrochloride was used as the anesthetic agent at an initial dose of 8 ml for an adult animal (474 kg to 560 kg). Repeated 4-ml doses were administered immediately upon return of sensation. The technique was found to be easily performed and effective for prolonged caudal epidural anesthesia in the horse.

A graphical analysis of the interrelationships among waterborne asbestos, digestive system cancer and population density

Five statistical procedures were used to partial the correlation between waterborne asbestos and digestive site cancer for the putative effects of population density. These include: analysis based on a data subset with roughly homogeneous population density; standard residual analysis (partial correlation); conditional probability integral transformation; analysis based upon ranked data, and use of logarithmic transformation. Nonparametric regression graphical techniques are applied to examine the nature or shape of the asbestos-cancer dose-response curve. Evidence is presented that suggests that there is considerable difference between analyses involving nonhigh-density tracts and non-San Francisco tracts. Evidence is also presented that the modal-type nonparametric regression curve forks or bifurcates when adjustment is made for population density.

Serological diagnosis of syphilis in pregnancy. Experiences at King Edward VIII Hospital, Durban

Three different serological screening tests for syphilis were performed at the 'booking' visit of 500 antenatal patients at the King Edward VIII Hospital, Durban. The prevalence of active syphilis was 7,4%. The rapid plasma reagent test not only had a high biological false-positive rate at 11,8%, but also failed to detect 18,9% of the 37 patients diagnosed as having syphilis by means of the IgM-specific fluorescent treponemal antibody absorption (FTA-ABS) test. The Treponema pallidum haemagglutination (TPHA) test had a similarly high biological false-positive rate of 15,8%, but did not miss any of the 37 cases of active syphilis. The TPHA test is therefore advocated for screening patients for syphilis.

Pharmacological modulation of neutrophil phagocytic function in a patient with recurrent sepsis, pyoderma gangrenosum and impaired phagocytosis

A 50-year-old man with recurrent life-threatening sepsis and a cutaneous condition resembling pyoderma gangrenosum, was found to have a defect of neutrophil phagocytic function. Phagocytosis could be enhanced by corticosteroids, both in vitro in a dose-dependent manner, and in vivo, when it was accompanied by rapid clinical improvement. Studies with steroid hormones and immuno-stimulatory drugs are described.

Procedure for recovery of enteroviruses from the Japanese cockle Tapes japonica

The most likely shellfish to be harvested if sportfishing is reinstated in San Francisco Bay is the Japanese cockle Tapes japonica. The virus levels present in these shellfish are unknown and need to be evaluated before the shellfish beds are open. Towards this end, a procedure for recovering and concentrating enteric viruses from these clams has been evaluated. Effective elution of poliovirus from clam tissues was found to occur with pH 9.5 glycine-buffered saline rather than with the pH 7.5 fluid utilized by other investigators on oysters. Poliovirus desorption was combined with Cat-Floc clarification to remove cytotoxicity from clam tissue homogenates. For assay purpose, viruses were concentrated by mixing the glycine supernatant with a beef extract solution, lowering the pH, and suspending the resulting floc in a small volume of phosphate buffer. This simple technique successfully recovered an average of 73% of the poliovirus added to clam homogenates at levels of 93 and 660 plaque-forming units per 100 g. Coxsackievirus B2 was isolated from clams exposed to raw sewage.