Thyrotoxic, hypokalaemic periodic paralysis in Australasian men.

Abstract The present study describes the clinical and laboratory features of 11 patients with thyrotoxic, hypokalaemic periodic paralysis, presenting to five Melbourne teaching hospitals between 1991 and 2000. All 11 patients were Asian or Polynesian men aged 18-41 years, and most had experienced previous episodes of acute, unexplained paralysis. All cases resolved without significant morbidity. Thyrotoxic, hypokalaemic periodic paralysis is a potentially life-threatening and terrifying condition, which is often under-recognized and will present with increasing frequency in the community. The diagnosis should be considered in any Asian-Australian male presenting with sudden onset paralysis.

Evaluation of thyroid stimulating hormone (TSH) alone as a first-line thyroid function test (TFT) in Papua New Guinea.

In the Port Moresby General Hospital, the Chemical Pathology Department assays both thyroid stimulating hormone (TSH) and free thyroxine (FT4) on all requests for a thyroid function test (TFT). The cost of assaying both tests is obviously higher than either test alone. In order to minimize the cost of a TFT we aimed to determine if TSH or FT4 alone as a first-line test would be adequate in assessing the thyroid hormone status of patients. We analyzed TFT records from January 1996 to May 2000 in the Port Moresby General Hospital. A total of 3089 TSH and 2867 FT4 were assayed at an annual reagent cost of Papua New Guinea kina 14,500. When TSH alone is used as a first-line test at the Port Moresby General Hospital, the biochemical status of 95% of patients will be appropriately categorized as euthyroidism, hypothyroidism or hyperthyroidism with only 5% discrepant (ie, normal TSH with abnormal FT4) results. In contrast, using FT4 alone as a first-line test correctly classifies only 84% of TFTs. Euthyroid status is observed in 50% of patients and FT4 assays on these samples will be excluded appropriately if a TSH-only protocol is adopted. Furthermore, we will save a quarter of the yearly cost of TFTs on reagents alone by performing TSH only. We conclude that TSH alone is an adequate first-line thyroid function test in Papua New Guinea and when it is normal no further FT4 test is necessary unless clinically indicated.

Immunoprophylactic strategies against respiratory influenza virus infection.

The objective of this report is to evaluate the prophylactic efficacy of liposome-mediated immunotherapy for prevention of respiratory influenza virus infection in mice. Antiviral antibody, interferon-gamma and poly (ICLC) were encapsulated in liposomes and they were evaluated for their ability to induce protective immunity against lethal influenza infection. Passive immunization using liposome-encapsulated antiviral antibody was found to offer complete protection against the virus challenge. However, this pretreatment must be administered within 24 h prior to virus challenge to be protective. Pretreatment with liposome-encapsulated interferon-gamma was found to stimulate cellular immune responses, but the protection is partial. Immunoprophylaxis using liposome-encapsulated double-stranded (ds) RNA poly (ICLC) provided complete and longer-lasting protection against influenza infection. These results suggest liposome-mediated immunoprophylactic approaches are effective in the prevention of respiratory influenza virus infection.

Superiority of traditional village diet and lifestyle in minimizing cardiovascular disease risk in Papua New Guineans.

In the traditional society of Papua New Guinea (PNG) atherosclerotic cardiovascular diseases (CVD) are rare. However, among the urban population reports of cases of atheroma-related CVD are increasing. The purpose of this study was therefore to compare the CVD risk factors in a homogeneous population of the Southern Highlands Province living in both rural and urban areas differing only in their diet and lifestyle. A total of 221 Samberigi people over the age of 25 years were selected for the survey. These included 123 individuals from remote villages of Samberigi and 98 of their relatives who had lived in Port Moresby city continuously for a minimum of 5 years. The anthropometric measurements, blood lipid, blood glucose and glycosylated haemoglobin (HbA1c) levels were measured and compared. The rural diets were mainly of vegetarian type, limited in variety and low in fat and protein content. In the urban subjects, the typical meal comprised refined foods with high fat and protein content. The urban men and women had significantly (p < 0.05) greater body weight, body mass index (BMI), and waist and hip circumferences than their rural counterparts. In Port Moresby, 57% of the men and 67% of the women were overweight or obese compared to 28% of their rural counterparts. Similarly, the mean plasma total cholesterol, low-density lipoprotein cholesterol (LDLC), high-density lipoprotein cholesterol (HDLC), fasting blood glucose and HbA1c were significantly higher in the urban group. However, no significant differences were demonstrated for waist to hip ratio, LDLC/HDLC ratio and lipoprotein (a) levels between the two groups. The total cholesterol, LDLC and HbA1c were positively associated with age and BMI in both rural and urban locations. In conclusion, there were significant increases in CVD risk factors in the urban population compared to the rural residents. This was predominantly due to the adoption of a western lifestyle and diet as people moved from rural villages to the city of Port Moresby.

Activation of the kallikrein kinin system in interstitial cystitis.

PURPOSE: We investigated whether the kallikrein kinin system is activated in interstitial cystitis by measuring urinary excretion rates of kinin peptides, active and total kallikrein, and the kininase neutral endopeptidase in women with interstitial cystitis. We compared these excretion rates to a control group of women with stress incontinence and normal bladder function. MATERIALS AND METHODS: Catheter urine was collected from subjects during a water diuresis (approximately 10 ml. per minute) before and after distention of the bladder with 100 ml. water. The contribution of the bladder wall to urinary kinins was assessed by measuring the change in kinin levels after 2 minutes of bladder stasis before and after distention. RESULTS: Absolute bradykinin and kallidin excretion rates were similar in women with interstitial cystitis and control subjects. Two minutes of bladder stasis after bladder distention increased urinary bradykinin (p = 0.02) but not kallidin excretion rates. Active and total kallikrein excretion rates were similar in patients with interstitial cystitis and control subjects. Neutral endopeptidase excretion rates were reduced in the initial urine collection from subjects with interstitial cystitis but were similar in both groups during later collection periods. CONCLUSIONS: These data provide evidence for increased bradykinin levels in the bladder wall of subjects with interstitial cystitis, which may be due in part to reduced neutral endopeptidase levels. These increased bradykinin levels may participate in the pathogenesis and symptomatology of interstitial cystitis.

Liposome-mediated immunotherapy against respiratory influenza virus infection using double-stranded RNA poly ICLC.

The use of liposome delivery technology to enhance the antiviral activity of poly ICLC (an immunomodulating dsRNA) while decreasing its intrinsic toxicity is evaluated in this study. The antiviral efficacies of free and liposome-encapsulated poly ICLC were evaluated and compared using a lethal respiratory influenza A virus infection in mice. The toxicity profiles of free and liposome-encapsulated poly ICLC were compared by determining the extent of hypothermia and loss in body weights in mice pretreated with these drugs. Poly ICLC was encapsulated in cationic liposomes prepared by the freeze drying method. To determine the antiviral efficacies of free and liposome-encapsulated poly ICLC, mice were intranasally pretreated with two doses of poly ICLC (free or liposomal, 1 mg/kg/dose) given 48 h apart. At various times post pretreatment, mice were intranasally challenged with 10 LD50 mouse-adapted influenza A/PR/8 (H1N1) virus. The survival rates of the mice were determined at day 14 post infected and compared to the untreated control mice. Results indicate mice pretreated with liposome-encapsulated poly ICLC within 3 weeks prior to virus challenge were completely protected (100% survival compared to 0% for the untreated control group, p < 0.001), while window of protection provided by free unencapsulated poly ICLC was 12 days. When the toxicity profiles of free and liposome-encapsulated poly ICLC were compared, it was found that hypothermia and body weight loss induced by poly ICLC were either completely mitigated or significantly reduced in mice given equivalent doses of poly ICLC in the liposome-encapsulated form. These results suggest that liposomes are an excellent drug carrier for poly ICLC, that liposome-encapsulated poly ICLC may provide a safe and effective immunotherapeutic approach for the prevention of respiratory influenza virus infections.

Review of cases of hyponatraemia in the Port Moresby General Hospital between August 1993 and June 1995.

Hyponatraemia (serum sodium level below 130 mmol/l) is a common electrolyte abnormality in a hospital population. It can be associated with dehydration, overhydration or normal hydration. Clinically, it is important to recognize the common diseases associated with hyponatraemia since correct treatment in terms of fluid replacement is essential in preventing complications of low serum sodium. We have reviewed results of serum sodium tested from patients admitted to the Port Moresby General Hospital between 1993 and 1995. This was aimed at identifying the most common features associated with low sodium. Clinical information and diagnosis were obtained by looking through a series of request forms. Of the approximately 30,000 blood samples taken over 23 months, the percentage of samples with hyponatraemia was about 1%. Hyponatraemia was more common in medical (38%) and paediatric (35%) cases and at the extremes of ages, ie, under the age of 6 years and above 40 years. Over a quarter of the hyponatraemic patients had severe hyponatraemia (serum sodium below 120 mmol/l). Clinical conditions commonly associated with hyponatraemia, in descending order of importance, were diarrhoea and vomiting, renal failure, central nervous system infections and trauma, pulmonary infections, oedematous states (eg, nephrotic syndrome) and diabetes mellitus.

Intranasal stimulation of long-lasting immunity against aerosol ricin challenge with ricin toxoid vaccine encapsulated in polymeric microspheres.

Intranasal (i.n.) immunization with ricin toxoid (RT) vaccine encapsulated in poly (lactide-co-glycolide) microspheres (RT-PLG-Ms) and poly (L-lactide) microspheres (RT-PLA-Ms) stimulated systemic and mucosal immune responses and protected mice from aerosolized ricin intoxication. High titers of anti-ricin IgG2a were stimulated in the serum of mice with one or two doses of RT-Ms 6 weeks postimmunization. However, in the lungs, no IgG2a or total IgG was elicited either with RT-Ms or with aqueous RT. At 6 weeks postimmunization, a single dose of the RT-Ms stimulated secretory IgA (sIgA) in the lungs of four of six mice, but a second immunizing dose did not enhance the stimulation. A single dose of aqueous RT vaccine failed to stimulate sIgA in the lungs, while, a second dose induced sIgA in 50% of the mice. One or two i.n. doses of RT-Ms protected most of the mice against lethal aerosol-delivered ricin toxin 6 weeks postimmunization. In contrast, protection was absent or marginal after one or two doses of aqueous RT vaccine. In both studies, the protection against lethal aerosol challenge was significantly better with one dose of RT-Ms than with two doses of aqueous vaccine, which may be attributed to the induction of sIgA in the lungs and the serum. Duration of the IgG2a and IgA in the serum, particularly that of IgG2a was much longer after the administration of RT-Ms than after the aqueous vaccine. The geometric mean IgG2a titers stimulated with two doses of RT-Ms remained high during 40 weeks postimmunization and were up to 25 times higher than the titers induced with aqueous RT vaccine. After 6 weeks, the IgG2a induced by two doses of aqueous vaccine was no longer detectable. Persistence of antibody response was predictive of efficacy. At 1 year postimmunization with two doses of RT-Ms, 100% of mice were protected against lethal ricin challenge. However, at the same time no protection was afforded by two doses of aqueous RT. The results of the present study consistently demonstrated the advantages of microencapsulated RT vaccine to stimulate effective and long-lasting protection by i.n. administration.

Antiviral activities of tragacanthin polysaccharides on Punta Toro virus infections in mice.

Tragacanthin polysaccharides from Astragalus brachycentrus (AV208) and Astragalus echidnaeformis (AV212) plants, which are devoid of in vitro antiviral activity, were evaluated in a mouse model of Punta Toro virus (PTV) infection. The PTV (a phlebovirus member of the Bunyaviridae family of viruses) is a model for studying the treatment of Rift Valley fever and hantavirus infections. Single intraperitoneal treatments with 12.5-200 mg/kg/day doses of AV212 given 24 h before or 4 and 24 h after virus inoculation protected the majority of mice from mortality. Single treatments with AV208 were ineffective when given 24 h before the virus challenge; however, protection was afforded when treatments were administered at 4 and 24 h following virus inoculation. In a follow-up study, AV208 treatments of 1.6-50 mg/kg/day given 24 h subsequent to virus exposure caused reductions in mortality, liver infection scores, liver and spleen virus titers, and serum transaminases. The polysaccharides did not activate lymphocytes or natural killer cells, nor was interferon induced in treated mice. However, mice pretreated with fumed silica (a macrophage poison) and infected with the PTV were not protected by subsequent administration of AV208 or AV212 at 50 mg/kg, providing evidence that activation of peritoneal macrophages by the polysaccharides affords protection to infected animals. These compounds should be considered for the potential treatment of significant human infections induced by bunyaviruses and hantaviruses.

Long-term treatment of malignant gliomas with intramuscularly administered polyinosinic-polycytidylic acid stabilized with polylysine and carboxymethylcellulose: an open pilot study.

Polyinosinic-polycytidylic acid stabilized with polylysine and carboxymethylcellulose (poly-ICLC) (10-50 mcg/kg, administered intramuscularly one to three times weekly) was given for < or = 56 months to 38 patients with malignant gliomas. There was minimal or no toxicity. Twenty of 30 patients (66%) receiving at least twice weekly poly-ICLC showed regression or stabilization of gadolinium-enhancing tumor, as revealed by magnetic resonance imaging (median = 65% volume decrease). All but one patient with anaplastic astrocytomas who received continuous poly-ICLC remain alive, with a median progression-free survival of 54 months from diagnosis. Median Kaplan-Meier survival is 19 months for patients with glioblastomas who receive at least twice weekly poly-ICLC treatments. Tumor response was associated with 2',5' -oligoadenylate synthetase activation (P = 0.03) but not with serum interferon. We hypothesize clinical activation by poly-ICLC of a basic host tumor suppressor system. Prolonged, quality survival with tumor stabilization or regression confirmed by magnetic resonance imaging for most patients with anaplastic astrocytomas and glioblastomas suggests that more extensive laboratory and controlled clinical studies are warranted. The concept of long-term, broad spectrum stimulation of host defenses with nontoxic, inexpensive double-stranded ribonucleic acids, such as low-dose poly-ICLC, may be applicable to the treatment of other malignancies.

Prophylactic and therapeutic efficacies of poly(IC.LC) against respiratory influenza A virus infection in mice.

Polyriboinosinic-polyribocytidylic acid [poly(IC.LC)] was evaluated for its prophylactic and therapeutic efficacies against respiratory influenza A virus infection in mice. Two doses of poly(IC.LC) (1 mg/kg of body weight per dose) administered intranasally within 12 days prior to infection with 10 50% lethal doses of mouse-adapted influenza A/PR/8 virus fully protected the mice against the infection. Determination of virus titers by hemagglutination and plaque assays showed more than a 2-log10 decrease in virus titers in lung homogenates of pretreated mice compared with those in the lungs of the nonpretreated group. Treatment of infected mice with poly(IC.LC) resulted in a modest (40%) survival rate. These results suggest that poly(IC.LC) provides a highly effective prophylaxis against respiratory influenza A virus infection in mice.

Characterization of the non-specific humoral and cellular antiviral immunity stimulated by the chloroform-methanol residue (CMR) fraction of Coxiella burnetii.

Modulation of the immune response by the chloroform-methanol residue (CMR) of phase I Coxiella burnetii whole cell was studied in Rift Valley fever virus-infected, or in naive endotoxin-non-responder C3H/HeJ mice. A single dose of CMR completely protected the mice from viral infection. Treating virus-infected mice with antibodies directed against interferons alpha/beta (IFN-alpha beta) and gamma (IFN-gamma) eliminated the CMR-induced protection. CMR stimulated the production of high levels of IFN-alpha/beta and 2'-5'-oligoadenylate synthetase activities in sera of the CMR-treated mice. IFN-gamma was present in supernatants of cultured spleen cells of CMR-treated, virus-infected mice, but not in their serum. Priming mice with CMR optimized the release of INF-gamma, interleukin-1 alpha (IL-1 alpha) and IL-6 from splenocytes in vitro. When stimulated in vitro, IL-2 and granulocyte-macrophage stimulating factor (GM-CSF) did not require in vivo priming for release from cultured spleen cells. Fluorescence-assisted cytometry of CMR-treated mouse spleen cells showed there was a CMR-dependent increase in the percentage of T-cells and Ia-positive T-cells. There also was a biphasic increase in the ratio between Th (L3T4) and Ts (Lyt2) cells. Biological activities stimulated by CMR indicate that CMR is a potent immunostimulant, which may modulate specific and non-specific antiviral responses.

Dependence of ricin toxoid vaccine efficacy on the structure of poly(lactide-co-glycolide) microparticle carriers.

Biodegradable microparticles made of poly(lactide-co-glycolide) (PLG) were used for protracted and pulsed-release of the incorporated ricin toxoid (RT) vaccine to reduce the multiple immunization doses and the time required to induce complete protection against lethal aerosol-borne ricin challenge. The release rate of RT encapsulated in PLG microparticles was controlled by polymer selection and varying the preparation procedures, which allowed us to control microparticle size and the distribution of the vaccine in the polymeric matrix. PLG-microparticles in which RT vaccine was distributed heterogeneously in small pockets stimulated a rapid antibody response which was independent of the polymeric composition of the carriers. PLG-microparticles in which RT vaccine was distributed homogeneously throughout the polymeric matrix induced a slower antibody response, which depended on the polymeric composition of the carriers. Administration of RT in homogeneous microparticles made from 50/50 PLG or 100% polylactide stimulated two distinct anti-ricin IgG peaks, while RT in heterogeneous microparticles stimulated identical IgG peaks. An early (3 weeks) and long-lasting (1 year or longer) anti-ricin antibody response was evoked by a single administration of encapsulated RT vaccine when prepared by the above-mentioned conditions. In contrast, three administrations of the aqueous RT were required to stimulate similar antibody response. Reduction of immunization time from 6 to 4 weeks was achieved with RT encapsulated in small homogeneous microparticles but not with homogeneous large microparticles. These results demonstrated the usefulness of biodegradable microparticles to improve the efficacy of immunization with RT vaccine and probably many other vaccines as well.

Efficacy of Coxiella burnetii and its chloroform-methanol residue (CMR) fraction against Rift Valley fever virus infection in mice.

Strains of Coxiella burnetii phase I and II whole cells (WC-I and WC-II) or whole cell fractions were assessed for their potential to induce long-lasting protection in endotoxin-non-responder C3H/HeJ or CD-1 mice against Rift Valley fever (RVF) virus challenge. Among the whole cell fractions, only the chloroform-methanol residue (CMR), administered as a single dose (100 micrograms per mouse) 24 h before viral challenge, effectively protected 100% of the mice from RVF virus; the CMR of the Ohio strain of C. burnetii was not protective. Most of the RVF virus-infected mice treated with other C. burnetii cell fractions died, although their times to death varied. Lipopolysaccharide (LPS) associated with CMR preparations used in these studies, did not protect against RVF virus challenge. A single dose of 100 micrograms of CMR given 24 h before viral challenge completely eradicated 4-5 logs of RVF virus in the serum, liver, spleen, and central nervous system. Compared to several other immunomodulators, CMR was an equally effective antiviral agent. Efficacy of CMR of both Henzerling and Ohio strains disappeared or was marginal when treatment was initiated 2-3 days before RVF viral challenge, even when a second or a third dose of CMR was administered after challenge. A single dose of liposome-encapsulated CMR to RVF virus-infected mice extended the range of therapeutic efficacy of this biologically active component of C. burnetii to 4 days before infection.

Antiviral and immunomodulating inhibitors of experimentally-induced Punta Toro virus infections.

A major component of a US Army Medical Research and Development Command-supported program to discover and develop new drugs for the treatment of Rift Valley fever, sandfly fever, and Crimean-Congo hemorrhagic fever has been to study candidate test materials against hepatotropic infections of C57BL/6 mice induced by the related but less biohazardous Punta Toro virus (PTV). The effects of 75 compounds, some of which were considered immunomodulators in their primary mechanism of activity, were studied in the PTV infection model. Of these, ribavirin, ribamidine, ribavirin 2',3',5'-triacetate, tiazofurin, tiazofurin-5'-monophosphate, tiazofurin-2',3',5'-triacetate, selenazofurin, pyrazofurin, 3-deazaguanine, and 3-deazaguanosine were considered significantly inhibitory, acting against the infection by a direct antiviral (non-immunomodulatory) fashion. These compounds had therapeutic indices (TI) ranging from > or = 5 to 65, using increased survivors as the evaluation parameter. Immunomodulators considered significantly inhibitory to this infection were poly (ICLC), ampligen, human recombinant interferon-alpha-A/D, MVE-1, MVE-2, AM-3, AM-5, mannozym, bropirimine, CL246,738, phenyleneamine, and 7-thia-8-oxoguanosine. Utilizing increased survivor numbers as measure of activity, these inhibitors had TI ranging from > or = 16 to 1000. Other antiviral effects exerted by the active compounds included reduction of hepatic icterus, lowered serum glutamic oxaloacetic and pyruvic acid transaminases, and inhibition of recoverable serum and liver virus titers. The active immunomodulators were significantly effective when therapy was initiated as late as 48 h after virus inoculation, at a time when clinical signs of the PTV disease were being manifested in the animal.

Potential role of immunomodulators for treatment of phlebovirus infections of animals.

Rift Valley fever (RVFV) is a major phlebovirus-induced epizootic disease of domestic animals (primarily cattle and sheep) in Africa. No therapies for the disease are known. A related phlebovirus, Punta Toro virus (PTV), has been adapted to induce an RVFV-like disease in C57BL/6 mice. This PTV infection has been used as a model for RVFV because it is reasonably safe and does not require high-level biologic containment. The infection model has been used to study the potential role of immunomodulating substances as therapies. A spectrum of immunomodulators has been studied; those immunomodulators most capable of preventing death and other disease manifestations are ampligen, bropirimine, poly (ICLC), AM-3, P-136, and 7-thia-8-oxoguanosine. An immunologic parameter common to all these substances has been their ability to induce interferon. Timing studies have indicated that these active substances may be administered therapeutically as well as prophylactically to inhibit markedly the progress of the disease. Further work is needed in the development of these materials for use in treating viral infections in domestic animals. As a next step, studies need to be run to compare the immunologic profiles induced by each substance in domestic animals and in mice.

Chemotherapeutic prevention of complications caused by vaccinia virus-vectored immunogen.

Vaccinia virus strains and constructs differ greatly in the number of PFUs required to produce tail lesions in the vaccinia virus mouse model. The pathogenesis of lesion formation appeared to involve virus spread from an initial focus in specific cells surrounding hair follicles to other concentrated areas of the dermis and finally, at the time of lesion development, to the epidermis. Antivirals that suppressed tail lesions, to a greater or lesser degree, included ara A, ribavirin, rifampicin, adenosine N'-oxide, and selected analogues. Immunomodulators, including ampligen and recombinant interferon, suppressed lesions at very low doses. Spread of virus infection from the dermis to the epidermis was inhibited as determined by immunofluorescence. These studies in the tail lesion model have suggested drugs that could be tested further in primate models of vaccinia virus infection. In addition, these studies provide additional data on a model that may be a useful adjunct in safety testing of recombinant vaccinia virus vaccines.

Effect of human, recombinant interleukin 2 on Punta Toro virus infections in C57BL/6 mice.

The effect of human recombinant interleukin-2 (rIL-2) on Punta Toro virus (PTV) infection was investigated in C57BL/6 mice. Immunologic and viral parameters were assessed after mice were treated i.p. with rIL-2 for 5 days. Treatment of mice with 25000 and 12500 units/mouse of rIL-2 resulted in significant inhibition of the disease as indicated by increases in survival of mice as well as decreases in liver and serum virus titers. Serum glutamic oxalic acid and pyruvic acid transaminase levels were also lowered indicating reduced liver damage. Murine IL-2 production returned to normal or above-normal levels in rIL-2 treated mice. Natural killer cell activity was also moderately stimulated by rIL-2 treatment. Significant amounts of interferon were not detected in the sera of treated mice. Weight gain and survival rates were similar for both toxicity and normal controls indicating that rIL-2 treatments had no toxic effect.