Thalassaemia. Part 3 of 3. Counselling and community education

In two previous articles, Simon Dyson, Verna Davis, and Raheya Rahman described the basic facts about thalassaemia and also considered the outcome of a preliminary survey establishing levels of awareness among community groups in one area. In this, the concluding article in the series, they look at the particular issues raised in thalassaemia counselling work and consider one approach to community education on the issue.

Thalassaemia: 2 of 3. Current community knowledge

In this second of three articles Simon Dyson, Verna Davis and Rafeya Rahman describe a study carried out in Manchester for the sickle-cell anaemia and thalassaemia centre to gauge the extent of community awareness about thalassaemia, the likely level of demand for further information and how that information might most usefully be given.

Thalassaemia: 1 of 3. Establishing basic awareness

Thalassaemia has until recently received little attention and consequently is not widely understood by health professionals, write Simon Dyson, Verna Davis and Rafeya Rahman. In the first of three articles they describe the illness and its treatment and the potential role for health visitors in supporting children with the condition and their families. They conclude with a brief questionnaire to test thalassaemia-awareness levels.

Hypoglycaemic activity of Coccinia indica and Momordica charantia in diabetic rats: depression of the hepatic gluconeogenic enzymes glucose-6-phosphatase and fructose-1,6-bisphosphatase and elevation of both liver and red-cell shunt enzyme glucose-6-phosphate dehydrogenase

Coccinia indica leaves were extracted with 60% ethanol, solvents were evaporated and the residue was suspended in water. This suspension was administered orally at a dose of 200 mg/kg body wt. after 18 h of fasting to normal fed and streptozotocin-induced male diabetic rats (180-250 g). After 90 min the rats were killed, and blood-glucose, hepatic glucose-6-phosphatase, fructose-1,6-bisphosphatase and glucose-6-phosphate dehydrogenase (G6PDH) and red-cell G6PDH were assayed. Blood sugar was depressed by 23% (P < 0.01) and 27% (P < 0.001) in the normal fed and streptozotocin-diabetic rats respectively compared with controls which were given distilled water. Hepatic glucose-6-phosphatase and fructose-1,6-bisphosphatase activities were depressed by 32% (P < 0.001) 30% (P < 0.05) respectively in the streptozotocin-diabetic rats, compared with 19% (P < 0.02) and 20% (P < 0.01) depression in the normal fed controls, whereas both the red-cell and hepatic G6PDH activities were found to be elevated by feeding the extract in the streptozotocin-diabetic and in the normal fed controls. Similar results were obtained with the 95%-ethanolic extract of Momordica charantia. Taken together, these results indicate that Coccinia indica and Momordica charantia extracts lowered blood glucose by depressing its synthesis, on the one hand through depression of the key gluconeogenic enzymes glucose-6-phosphatase and fructose-1,6-bisphosphatase and on the other by enhancing glucose oxidation by the shunt pathway through activation of its principal enzyme G6PDH.

Delineation of immunoreactive, conserved regions in the external glycoprotein of the human immunodeficiency virus type 1

Immunization of mice and rats with purified external glycoprotein gp120 from two divergent human immunodeficiency virus type 1 (HIV-1) isolates resulted in the development of seven hybridomas secreting monoclonal antibodies able to recognize regions of gp120 which are common among divergent strains of HIV-1. These monoclonal antibodies cross-reacted with env glycoproteins from one African (Rutz), one Haitian (RF), and three North American viral isolates, namely IIIB, MN, and 451 by either immunoblot or radioimmunoprecipitation assays. All recognized denatured gp120 in immunoblots with the exception of one which required a conformationally intact glycoprotein for reactivity. The gp120 epitopes identified by these antibodies were mapped by screening of an env gene library in the lambda gt11 expression system. Three out of four epitopes were found to reside in the amino-terminal half of gp120 (Cys9 to Cys35, Thr44 to Glu72 and Val108 to Met130), the other was located in the middle region (Thr221 to Ser255). By virtue of their extent of cross-reactivity these reagents might provide a unique resource for the detection of new viral isolates related to HIV-1.

Hypoglycemic effects of Coccinia indica: inhibition of key gluconeogenic enzyme, glucose-6-phosphatase

Coccinia indica (Family: Cucurbitaceae, locally known as telakucha) leaves were extracted with 95% ethanol. Following evaporation of the solvents, the residue was suspended in distilled water. When this suspension was fed orally to male normal-fed and 48-hr starved rats, the blood glucose was lowered 21% (P less than 0.01) in normal-fed and 24% (P less than 0.001) in 48-hr starved animals respectively. Starvation had induced a 3-fold increase in the activity of glucose-6-phosphatase and this activity was depressed 19% (P less than 0.05) by extract feeding while basal activity of the enzyme in normal-fed rats remained unaffected. Consistent with the depression of glucose-6-phosphatase, urea cycle enzyme arginase was also depressed 21% (P less than 0.001) and 12% (P less than 0.01) in the liver of 48 hr-starved and normal-fed animals respectively. Unlike glucose-6-phosphatase, starvation induced levels of gluconeogenic enzymes alanine aminotransferase and aspartate aminotransferase were not affected by Coccinia extract. These results suggest that the hypoglycemic effect of C. indica is partly due to the repression of the key gluconeogenic enzyme glucose-6-phosphatase.

Renal cell carcinoma treated with continuous-infusion interleukin-2 with ex vivo-activated killer cells

High-dose recombinant interleukin-2 (rIL-2) results in tumor responses in patients with metastatic renal cell carcinoma ranging from 9 to 31%. Continuous infusion regimens of rIL-2 may be less toxic and may result in greater in vivo lymphokine-activated killer (LAK) cell production. The current trial used a continuous infusion of rIL-2 with ex vivo LAK cells. These cells were pretreated with phenylalanine methyl ester to remove monocytes to allow cell culture at higher concentrations. Twenty-three patients were entered into the trial. Two patients had complete responses (9%) lasting 15+ and 20+ months. Four patients had partial responses (17%) of 9+, 6+, 3, and 3 months, respectively. One partial responder at 9+ months had only minimal residual retroperitoneal disease that may represent scar tissue. All responders had prior nephrectomies. All but one of the responding patients completed a full cycle of rIL-2 at the highest (starting) dose, 6 x 10(6) U/m2. This rIL-2/LAK regimen appears to be an effective therapy for metastatic renal cell carcinoma.

Characterization of a neutralizing monoclonal antibody to the external glycoprotein of HIV-1

The major neutralizing epitope on the external glycoprotein of HIV-1 was studied with an envelope-specific monoclonal antibody and with a human serum positive for antibodies to HIV-1 proteins, both of which were able to neutralize virus infectivity. The monoclonal antibody reacted specifically with gp120 from HIV-1IIIB, and was shown to neutralize infection of CEM cells by cell-free virions, and inhibited the formation of syncytia normally observed when uninfected cells are cocultured with HIV-1-infected cells. Similar neutralization of viral infection and inhibition of syncytia formation was also demonstrated by the HIV-1-antibody-positive human serum. By examining a number of overlapping peptides from a region of HIV-1 gp120 known to contain a neutralizing epitope, this epitope was localized between amino acids 307 and 320 (V3 loop) in the external glycoprotein molecule. The monoclonal antibody did not interfere with the binding of gp120 to CD4, or with the subsequent step of CD4-induced shedding of gp120 from the viral envelope. However, it blocked the proteolytic cleavage of the V3 loop by thrombin, suggesting that the antibody may be inhibiting the interaction of the loop with other membrane-bound proteins.

Interleukin-2 with ex vivo activated killer cells: therapy of advanced non-small-cell lung cancer

A phase II study was conducted to examine the efficacy of interleukin-2 (IL-2) with lymphokine-activated killer (LAK) cells as therapy for advanced non-small-cell lung carcinoma (NSCLC). IL-2 was administered at a fixed dose of 6 x 10(6) U/M2 per day as a 24 h continuous intravenous infusion (CIV) with LAK cells. Eleven patients were entered onto this study and six were evaluable. One patient had a near complete response of 18 months duration. Only two patients were able to complete the regimen without dose reduction. This regimen was poorly tolerated with pulmonary toxicity being the major problem. The partial responder was the only patient to undergo more than one course of therapy. IL-2/LAK therapy may have activity in NSCLC and further studies are warranted in this uniformly fatal disease. However, future studies will have to incorporate less toxic IL-2 regimens.

Unusual gastrointestinal complications of interleukin-2 therapy

Minor and reversible gastrointestinal side effects are common when patients receive interleukin-2 (IL-2) with or without lymphokine-activated killer (LAK) cells. We treated 42 cancer patients with IL-2 therapy and 3 patients developed serious gastrointestinal problems during treatment. Complications included sigmoid colon perforation, ischemic necrosis of the small and large intestine, and diffuse bowel ulceration. These were not associated with tumor implants or hypotension. Two patients died as a direct result of these problems despite aggressive surgical and medical management. The incidence of major gastrointestinal complications with IL-2 therapy may be greater than previously reported and a heightened awareness of potential gastrointestinal problems may circumvent considerable morbidity and mortality.

Interleukin-2 lymphokine-activated killer cell therapy of non-Hodgkin's lymphoma and Hodgkin's disease

We conducted a phase II study utilizing interleukin-2 (IL-2) with lymphokine-activated killer (LAK) cells as therapy for non-Hodgkin's lymphoma (NHL) and Hodgkin's disease (HD). IL-2 was given at a fixed dose of 3 x 10(6) U/m2/day administered as a 24-h continuous intravenous infusion with LAK cells. Nineteen extensively treated patients were entered and 15 were evaluable. In general, this regimen was reasonably well tolerated with mild toxicities that were rapidly reversible. Patients who completed therapy did so without dose attenuations. However, discontinuation of therapy was necessary in four patients due to atypical toxicities that were not clearly dose related. Two patients (one NHL and one HD) had partial remissions of brief duration, four had disease stabilization, and seven had progressive disease. While there were not sufficient numbers to evaluate critically any NHL or HD subtype, this regimen does not appear to have significant activity for either disease.

Detection of Vibrio cholerae O1 in the aquatic environment by fluorescent-monoclonal antibody and culture methods

Vibrio cholerae O1 in plankton samples collected from ponds and rivers between February 1987 and January 1990 in Matlab, Bangladesh, was detected by the fluorescent-monoclonal antibody (FA) technique. Samples were collected at sites which were monitored fortnightly (fixed sites) as well as at sites that were part of a case-control study. FA results were compared with those obtained by conventional culture methods (CM). A total of 876 samples were collected; V. cholerae O1 was detected in 563 samples (64.27%) by the FA method and in 3 samples (0.34%) by CM. Of the fixed-site plankton samples, 439 (63.62%) were positive by FA and none were positive by CM. Of the 93 case sites sampled on the day after the occurrence of a case of cholera, 73 (78.49%) were positive for V. cholerae O1 by FA and 3 (3.2%) were positive by CM. In comparison, of the 93 first-day sample collections at control sites at the time a case of cholera occurred, only 51 (54.83%) were positive by FA and none were positive by CM. From the data, it is concluded that V. cholerae O1 is present throughout the year in the ponds and rivers of Bangladesh that were examined in this study and that V. cholerae can be detected by FA but not always by CM. The FA procedure was found to be very useful in detecting V. cholerae in plankton, with which it was associated and often occurred in large numbers in the nonculturable stage. Thus, studies investigating the significance of the role of environmental factors in the epidemiology of cholera can be performed effectively by using FA. Such studies are in progress.

Characterization of the secreted, native gp120 and gp160 of the human immunodeficiency virus type 1

We have previously shown that the cell line 6D5(451) chronically infected with the HIV-1 isolate HTLV-III(451), secretes the HIV-1 envelope glycoproteins gp120 and gp160 in the extracellular medium. The HTLV-III(451) gp120 and gp160 were purified by sequential affinity chromatographic steps using a monoclonal antibody to HIV-1 gp41 and an anti-HIV-1-positive human serum. Amino acid sequence analysis of gp120 and gp160 showed the loss of the signal peptide. Digestion of the purified gp120 and gp160 with endoglycosidases revealed that both proteins are heavily glycosylated and contain complex carbohydrates, in contrast to the intracellular form of gp160 which has been shown to contain mannose-rich immature sugars. Competitive binding analysis showed that while both gp120 and gp160 bind CD4, the affinity of gp160 was five times lower than that of gp120. Both gp120 and gp160 inhibited syncytia formation by HIV-1-infected cells when mixed with CD4+ cells. Furthermore, both gp120 and gp160 had strong mitogenic effects on the T cells from HIV-1-infected gibbons but not on cells from uninfected gibbons.

Monoclonal antibodies to HTLV-III451 gp41: delineation of an immunoreactive conserved epitope in the transmembrane region of divergent isolates of HIV-1

We report on the development of monoclonal antibodies directed against the transmembrane portion of the envelope of HTLV-III451 gp41. One of these monoclonal antibodies, designated M71/2B4, was found to cross-react with transmembrane proteins from other independent isolates of HIV-1, namely IIIB, MN, and RF. Thus, this monoclonal antibody identifies an epitope located in a region of gp41 that is conserved among all these isolates. To identify this conserved region a series of E. coli recombinant proteins were screened in immunoblot with M71/2B4. From these results the epitope recognized by this antibody appears to map at the amino terminus of gp41, in the region indicated between the cleavage site with gp120 (aa 508) and the HindIII site (aa647).

Oral cholera vaccines containing B-subunit-killed whole cells and killed whole cells only. II. Field evaluation of cross-protection against other members of the Vibrionaceae family

Because of demonstrable cross-reactivity of cellular antigens contained in B subunit-killed whole-cell (BS-WC) and killed whole-cell-only (WC) oral cholera vaccines with antigens of various non-cholera species of the family Vibrionaceae (NCV), the protection conferred by the vaccines against diarrhoea associated with NCV was evaluated during a randomized, double-blind field trial in Bangladesh. Children aged 2-15 years and women aged greater than 15 years (62,285 in number) received three doses of BS-WC vaccine, WC-only vaccine, or a placebo consisting of Escherichia coli K12 strain (K12). During 1 year of follow-up, the incidence of treated episodes of diarrhoea associated with non-cholera vibrios known to be enteric pathogens (non-01 Vibrio cholerae, V. fluvialis, V. parahaemolyticus, V. mimicus) in the placebo group was low (1.9 cases per 10,000 recipients) and identical to that for the two vaccine groups combined. The incidence (per 10,000 recipients) of treated diarrhoeal episodes associated with Aeromonas species was considerably higher, but nearly identical in the three groups (26.1 cases for BS-WC, 26.0 cases for WC; 25.9 cases for K12). Pleisiomonas shigelloides was not isolated from any participant. It is concluded that NCV other than Aeromonas were rarely isolated from diarrhoeal patients in our study population and that killed oral vaccines which were effective against cholera exhibited no detectable cross-protection against diarrhoea associated with NCV organisms.

Immunological and chemical analysis of P6, the carboxyl-terminal fragment of HIV P15

The first open reading frame of the HIV genome has been identified as the gag gene. The proteins encoded by this gene are p17 as the amino-terminal protein, p24 as the middle peptide, and p15 as the carboxyl-terminal end. A monoclonal antibody recognizing an antigenic determinant on a fragment of p15 has been developed and designated M35/2F8. This monoclonal has been instrumental in radiosequencing the carboxyl-terminal product of p15, p6, and in determining the cleavage site between this protein and the amino-terminal product, p7. By immunoaffinity chromatography it was also possible to purify p6 from HIV lysates and all p6 containing polyproteins from HIV-infected cells. These results gave more insight into the composition and processing of the HIV gag gene.

Characterization of highly immunogenic p66/p51 as the reverse transcriptase of HTLV-III/LAV

Approximately 80 percent of all human sera that react with antigens of HTLV-III, the etiologic agent of the acquired immune deficiency syndrome (AIDS), recognize protein bands at 66 and 51 kilodaltons. A mouse hybridoma was produced that was specific to these proteins. Repeated cloning of the hybridoma did not separate the two reactivities. The p66/p51 was purified from HTLV-III lysates by immunoaffinity chromatography and subjected to NH2-terminal Edman degradation. Single amino acid residues were obtained in 17 successive degradation cycles. The sequence determined was a perfect translation of the nucleotide sequence of a portion of the HTLV-III pol gene. The purified p66/51 had reverse transcriptase activity and the monoclonal immunoglobulin G specifically removed the enzyme activity from crude viral extract as well as purified enzyme.

Distinction of human T-cell line (HUT-102)-derived activity stimulating granulocytic colony formation in diffusion chambers in vivo from activities stimulating erythroid and mixed-colony formation in vitro

Medium conditioned in the presence of human HUT-102 T-cell line cells contains activities stimulating human mixed (colony-forming unit, erythroid, granulocyte, macrophage, megakaryocyte) and erythroid (burst-forming unit, erythroid) colony formation in methylcellulose in vitro and granulocyte colony formation in diffusion chambers in mice. The stimulatory effect of HUT-102-conditioned medium on colony-forming unit, granulocyte diffusion chamber was also observed in diffusion chambers implanted in nude mice. The hemopoietic activities were heat stable and could be detected from serum-free conditioned medium. Chromatographically, it was possible to separate colony-forming unit, granulocyte diffusion chamber-stimulating activity from activities stimulating burst-forming unit, erythroid and colony-forming unit, erythroid, granulocyte, macrophage, megakaryocyte. On the other hand, the latter two activities were indistinguishable by the methodology used in this study. Failure to abolish the hemopoietic activities by boiling or by human T-lymphotropic retrovirus type 1 antibody indicates that human T-lymphotropic retrovirus type 1 or its components potentially present in the conditioned medium were not responsible for the stimulatory effects.

Effects of insulin on CO2 fixation in adipose tissue. Evidence for regulation of pyruvate transport

Insulin was found to double the rate of incorporation of H14CO3- into protein by segments of rat epididymal adipose tissue provided the incubation medium contained a suitable energy substrate such as fructose. Overall protein synthesis was increased by insulin to a lesser extent, one-third as measured by tritiated water indicating that insulin also increased CO2 fixation into amino acids. The latter could be demonstrated only when the tissue amino acid pools were expanded by the addition of aspartate to the incubation medium. The pattern of labeling observed in the amino acids indicated that CO2 fixation occurred primarily at the pyruvate carboxylase step. Addition of pyruvate to the incubation medium also increased CO2 fixation and this effect was not additive with that of insulin, suggesting that insulin acted by increasing the availability of pyruvate to the carboxylase. No change in carboxylase activity could be measured. Mitochondria isolated from tissue exposed to insulin retained a higher capacity to fix CO2 into acid-soluble products provided they were not freeze-thawed or sonicated. Uptake of pyruvate by mitochondria incubated 1 min at 2 degrees C or 5 s at 15 degrees C was doubled by prior insulin treatment of the tissue. It is concluded that insulin increases the flux through pyruvate carboxylase in adipose tissue in part by increasing the transport of pyruvate through the inner mitochondrial membrane.

Ecological relationships between Vibrio cholerae and planktonic crustacean copepods

Strains of Vibrio cholerae, both O1 and non-O1 serovars, were found to attach to the surfaces of live copepods maintained in natural water samples collected from the Chesapeake Bay and Bangladesh environs. The specificity of attachment of V. cholerae to live copepods was confirmed by scanning electron microscopy, which revealed that the oral region and egg sac were the most heavily colonized areas of the copepods. In addition, survival of V. cholerae in water was extended in the presence of live copepods. Attachment of viable V. cholerae cells to copepods killed by exposure to -60 degrees C was not observed. Furthermore, survival of V. cholerae was not as long in the presence of dead copepods as in the live copepod system. A strain of Vibrio parahaemolyticus was also seen to attach to copepod surfaces without effect on survival of the organism in water. The attachment of vibrios to copepods was concluded to be significant since strains of other bacteria, including Pseudomonas sp. and Escherichia coli, did not adhere to live or dead copepods. Attachment of V. cholerae to live copepods is suggested to be an important factor of the ecology of this species in the aquatic environment, as well as in the epidemiology of cholera, for which V. cholerae serovar O1 is the causative agent.

Sexual differentiation of hepatic metabolism of corticosterone and testosterone in the rat

The metabolism of corticosterone and testosterone has been studied in vitro in separate aliquots of the same homogenates of livers from neonatally masculinized and non-masculinized adult castrate male rats. The recovered metabolites were separated by TLC and identified by the combined use of GLC and appropriate derivative formation. The major effect of neonatal masculinization upon the metabolism of both steroids was to increase the ratio of 3 beta : 3 alpha metabolites but this effect was much more prominent in the metabolism of corticosterone than of testosterone. Only 5 alpha metabolites of corticosterone were found, whereas a minor amount of 5 beta products appeared in the case of testosterone. Reduction at C-20 accounted for only about 5% of the metabolism of corticosterone with the exclusive formation of 20 beta-hydroxy derivatives in the non-masculinized liver, but of both 20 alpha and 20 beta products in the masculinized liver. Small amounts of acetylated androstane 3,17-diols and 3-hydroxy-17-ketones were formed, apparently by enzymic reactions that are influenced by neonatal masculinization.