Synergy of antithrombin III concentrate and antivenom in preventing coagulopathy in a rat model of Malayan pit viper envenoming

The effects of unrefined equine antivenom and antithrombin III (AT-III) concentrate on the coagulopathy induced by systemic envenomation by Malayan pit viper (Calloselasma rhodostoma; MPV) venom were investigated in a rat model. 37 rats received an intramuscular injection of MPV venom and serial blood samples were taken from the femoral vein for simple whole blood clotting tests and measurement of AT-III activity. 30 min after venom injection, treatment (antivenom, AT-III or both) was given intravenously. 6 rats were untreated and all developed uncoagulable blood and AT-III depletion 90-210 (median 180) min after venom injection. A combination of high dose AT-III concentrate (0.5 units/g) and antivenom (20 micrograms/g) prevented abnormal clotting (P less than 0.001), whereas AT-III alone, antivenom alone, or a combination of low dose AT-III (0.25 units/g) and antivenom did not (P less than 0.05). These results suggest that the coagulation abnormality in MPV envenomation is secondary to activation of the coagulation cascade at several levels, and that treatment with antivenom alone may not be sufficient to reverse or prevent this phenomenon.     

Microcirculation of the healthy human gingiva

 The purpose of this study was to evaluate the microcirculation in healthy human gingiva. Forty-two adult volunteers with clinically healthy gingiva participated. The ages of this research sample ranged from 20 to 30 years. Periodontal conditions were evaluated and assessed by using the qualitative plaque index, gingival index, gingival bleeding index, tooth mobility, and laser Doppler flow-metry (LDF) on 12 maxillary and mandibular anterior teeth. The LDF data were recorded on the facial aspect of the free gingiva, interdental gingiva, attached gingiva, and alveolar mucosa of 12 maxillary and mandibular anterior teeth, utilizing an acrylic stent to stabilize the probe. This technique was then modified to circumvent contamination by saliva and gingival exudate. Blood flow in the maxillary anterior gingiva differed significantly from that in the mandibular anterior gingiva in interdental gingiva, attached gingiva, and alveolar mucosa, at P < 0.01. The maxillary anterior gingiva, at each point on the stent, showed significant differences in the mean LDF, at P < 0.01. For the mandibular anterior gingiva, the difference was significant only in the alveolar mucosa region. Received: November 10, 2000 / Accepted: January 23, 2002     

Cutaneous manifestations in HIV positive patients

Cutaneous manifestations are common clinical findings among HIV positive patients. The causes may be bacteria, viruses, fungi and other non-infectious agents. This study was conducted at the Pramongkutklao Hospital skin clinic to determine the frequency distribution of cutaneous manifestations in HIV positive patients. A total of 147 patients with HIV seropositivity were recruited and divided into a retrospective group and a prospective study group. For the retrospective study, hospital records of 129 patients who attended from January 1995 to November 1998 were recruited. The prospective study was carried out from November 1998 to January 1999 and 18 patients were recruited. Cutaneous finding among patients in the two studies were evaluated. There were ten common cutaneous manifestations observed in the retrospective and prospective study including pruritic papular eruptions (PPE) (51.2%, 50%), oral candidiasis (16.7%, 21.7%), herpes zoster (10.9%, 5.6%), oral hairy leukoplakia (10%, 5.6%), unclassified eczema (9%, 11.1%), urticaria (5.6%, 3.1%), seborrheic dermatitis (4.7%, 16.7%), folliculitis (4.7%, 5.6%), prurigo simplex (4.7%, 5.6%), and Steven-Johnson syndrome (3.9%, 0%). However, the distribution of cutaneous manifestations in the two studies were not significantly different. These findings may be useful as baseline data for common cutaneous manifestations in HIV positive patients.     

Adherence of human eosinophils to infective filariform larvae of Necator americanus in vitro

Eosinophilia is common in hookworm infection but the interaction between eosinophils and the larval stage of the parasite is poorly understood. The present study was conducted to test the ability of the eosinophils to adhere to infective filariform larvae of Necator americanus in vitro. Adherence of eosinophils to the larvae was found to be serum dependent. Antibody facilitated eosinophil adherence but this was maximal in the presence of complement. The adherence was greatly diminished by EGTA treated normal human serum (NHS) and was completely abolished when NHS was treated with either EDTA or heat-inactivation, suggesting that the process can be facilitated through complement activation via the alternative pathway. As with other nematodes, the surface of hookworm larvae appeared to be both antigenic and complement-activating. Although it is not known whether eosinophil adherence has any larvicidal effect, the present study demonstrated for the first time a definite interaction between human eosinophils and hookworm filariform larvae.     

The hyaluronidase activities of some Southeast Asian snake venoms

The hyaluronidase activities of venoms of snakes indigenous to Southeast Asia were investigated. With the exception of the venom of the Malayan krait Bungarus candidus, the elapid venoms had either little or no hyaluronidase activities, whereas the viperid venoms possessed considerable activity. A component of Russell's viper venom with hyaluronidase activities had a mol. wt of approximately 14,000. Neither MP4, a monoclonal antibody raised against the purified Russell's viper venom hyaluronidase toxin, nor a monospecific polyclonal antivenom neutralized the hyaluronidase activities of this purified hyaluronidase component of crude Russell's viper venom. The Russell's viper venom hyaluronidase activities was labile on heating and storage. The significance of these observations to envenomation and antivenom production is discussed.     

Effect of triclosan on healing following non-surgical periodontal therapy in smokers

BACKGROUND: Tobacco smoking is an established risk factor for periodontitis, and is associated with periodontal attachment and tooth loss. Clinical studies have indicated that smoking may adversely affect and impede healing following periodontal therapy. Adjunctive antimicrobials, on the other hand, have been shown to enhance the effect of non-surgical periodontal therapy. The objective of this study was to evaluate the effect of a triclosan/copolymer/fluoride dentifrice on healing following non-surgical periodontal therapy in smokers. METHODS: Sixty smokers (aged 35-59 years; 23 females) with chronic periodontal disease volunteered to participate in a double-blind, randomized, controlled, clinical trial. The subjects were randomly assigned to use a triclosan/copolymer/fluoride (30 subjects) or a standard fluoride (30 subjects) dentifrice and received detailed information on proper techniques for self-performed plaque control. The participants then received non-surgical periodontal therapy followed by periodontal maintenance care every 6 months over 24 months. Clinical recordings included evaluation of oral hygiene standards, gingival health, and periodontal status. RESULTS: Subjects using the triclosan/copolymer/fluoride dentifrice exhibited significantly improved oral hygiene conditions, gingival health, and periodontal status compared with those using the standard fluoride dentifrice over the 24-month maintenance interval. CONCLUSIONS: The results suggest that an oral hygiene regimen including a triclosan/copolymer/fluoride dentifrice may sustain the short-term effect of non-surgical periodontal therapy in smokers.     

Immunogenicity of two formulations of oral cholera vaccine comprised of killed whole vibrios and the B subunit of cholera toxin.

Two formulations of oral cholera vaccine were evaluated for safety and immunogenicity in adult volunteers in Thailand, an area with sporadic cholera outbreaks. One formulation consisted of 2 x 10(11) killed vibrios and 5 mg of cholera toxin B subunit, as was previously evaluated in North American volunteers, and the other consisted of 1 x 10(11) killed vibrios and 1 mg of B subunit, as was recently evaluated in a field trial in Bangladesh. Three doses of each formulation were given with citrate-bicarbonate buffer. Neither formulation had adverse effects. The formulations stimulated similar serum immunoglobulin G (IgG) and IgA responses to Vibrio cholerae lipopolysaccharide and cholera toxin and intestinal secretory IgA responses to lipopolysaccharide and toxin after three doses. The formulation containing twice the quantity of killed vibrios stimulated better vibriocidal responses, especially to Ogawa serotype. A formulation of oral vaccine containing more killed vibrios than were included in the vaccine studied in the Bangladesh field trial may provide greater protection against cholera.     

Comparison of the reactivities and immunogenicities of procholeragenoid and the B subunit of cholera toxin in Thai volunteers.

Procholeragenoid, a stable high-molecular-weight aggregate of cholera toxin derived by heat treatment, was evaluated for reactivity and immunogenicity in adult Thai volunteers. Since procholeragenoid is known to retain some residual activity of cholera toxin, increasing amounts were ingested until diarrhea occurred; 250 micrograms induced diarrhea, but 100 micrograms did not. Procholeragenoid and cholera toxin B subunit, both in 100-micrograms amounts, were then compared for systemic and intestinal antitoxin responses. When three peroral doses were given, these immunogens gave comparable responses. The secretory immunoglobulin A antitoxin responses to three doses of 100 micrograms of B subunit did not differ significantly from responses found in previous studies of Thai adults given 1 or 5 mg of B subunit, but serum antitoxin responses were less after 1 or 2 doses of 100 micrograms than after doses of 1 or 5 mg. Serum antitoxin levels were similar after 3 doses of B subunit. Procholeragenoid in the maximum safe dose of 100 micrograms does not offer any immunologic advantage over B subunit, although it may be less expensive and easier to produce. However, these studies suggest that higher amounts of B subunit are more immunogenic and may be preferable, if found to be sufficiently cost effective, when added to oral killed whole Vibrio cholerae vaccines.