The effectiveness of telehealth interventions in suicide prevention: A systematic review and meta-analysis

BACKGROUND

Suicidal attempt is a significant risk factor for future attempts, with the highest risk during the first-year post-suicide. Telepsychiatry has shown promise by providing easy access to evidence-based interventions during mental health crises.

AIMS

investigation the effectiveness of telehealth interventions in suicide prevention.

METHODS

Four electronic databases (PubMed, Scopus, Web of Science, and Ovid) were systematically searched for studies on patients undergoing telepsychiatry intervention (TPI) up to June 2022. Following PRISMA guidelines, a systematic review and meta-analysis were conducted to investigate the effectiveness of telehealth interventions in suicide prevention. Continuous data were pooled as standardised mean difference (SMD), and dichotomous data were pooled as risk ratio using the random effects model with the corresponding 95% confidence intervals (CI).

RESULTS

Sixteen studies were included in the review. Most studies were case-control and randomised controlled trials conducted in Europe and North America. The findings of the studies generally showed that TPIs are effective in reducing suicide rates (odds ratio = 0.68; 95% CI [-0.47, 0.98], p = .04) and suicidal reattempts. The interventions were also found to be well-accepted, with high retention rates.

CONCLUSION

Our results suggest that TPIs are well-accepted and effective in reducing suicide rates and reattempts. It is recommended to maintain telephone follow-ups for at least 12 months. Further research is needed to understand the potential of telepsychiatry in suicide prevention fully.

Association of serum leptin and ghrelin levels with smoking status on body weight: a systematic review and meta-analysis

Background and aims

Smoking cigarettes is a major global health problem that affects appetite and weight. The aim of this systematic review was to determine how smoking affected plasma leptin and ghrelin levels.

Methods

A comprehensive search of PubMed, Scopus, Web of Science, and Ovid was conducted using a well-established methodology to gather all related publications.

Results

A total of 40 studies were included in the analysis of 11,336 patients. The overall effect showed a with a mean difference (MD) of -1.92[95%CI; -2.63: -1.20] and p = 0.00001. Subgroup analysis by study design revealed significant differences as well, but with high heterogeneity within the subgroups (I2 of 82.3%). Subgroup by sex showed that there was a significant difference in mean difference between the smoking and non-smoking groups for males (MD = -5.75[95% CI; -8.73: -2.77], p = 0.0002) but not for females (MD = -3.04[95% CI; -6.6:0.54], p = 0.10). Healthy, pregnant, diabetic and CVD subgroups found significant differences in the healthy (MD = -1.74[95% CI; -03.13: -0.35], p = 0.01) and diabetic (MD = -7.69[95% CI, -1.64: -0.73], p = 0.03). subgroups, but not in the pregnant or cardiovascular disease subgroups. On the other hand, the meta-analysis found no statistically significant difference in Ghrelin serum concentration between smokers and non-smokers (MD = 0.52[95% CI, -0.60:1.63], p = 0.36) and observed heterogeneity in the studies (I2 = 68%).

Conclusion

This study demonstrates a correlation between smoking and serum leptin/ghrelin levels, which explains smoking's effect on body weight.

Systematic review registration

https://www.crd.york.ac.uk/ prospero/display_record.php, identifier (Record ID=326680).

Deep-learning CT reconstruction in clinical scans of the abdomen: a systematic review and meta-analysis

OBJECTIVE

To perform a systematic literature review and meta-analysis of the two most common commercially available deep-learning algorithms for CT.

METHODS

We used PubMed, Scopus, Embase, and Web of Science to conduct systematic searches for studies assessing the most common commercially available deep-learning CT reconstruction algorithms: True Fidelity (TF) and Advanced intelligent Clear-IQ Engine (AiCE) in the abdomen of human participants since only these two algorithms currently have adequate published data for robust systematic analysis.

RESULTS

Forty-four articles fulfilled inclusion criteria. 32 studies evaluated TF and 12 studies assessed AiCE. DLR algorithms produced images with significantly less noise (22-57.3% less than IR) but preserved a desirable noise texture with increased contrast-to-noise ratios and improved lesion detectability on conventional CT. These improvements with DLR were similarly noted in dual-energy CT which was only assessed for a single vendor. Reported radiation reduction potential was 35.1-78.5%. Nine studies assessed observer performance with the two dedicated liver lesion studies being performed on the same vendor reconstruction (TF). These two studies indicate preserved low contrast liver lesion detection (> 5 mm) at CTDIvol 6.8 mGy (BMI 23.5 kg/m2) to 12.2 mGy (BMI 29 kg/m2). If smaller lesion detection and improved lesion characterization is needed, a CTDIvol of 13.6-34.9 mGy is needed in a normal weight to obese population. Mild signal loss and blurring have been reported at high DLR reconstruction strengths.

CONCLUSION

Deep learning reconstructions significantly improve image quality in CT of the abdomen. Assessment of other dose levels and clinical indications is needed. Careful choice of radiation dose levels is necessary, particularly for small liver lesion assessment.

Calciphylaxis in uraemic and nonuraemic settings: clinical risk factors and histopathological findings

BACKGROUND

Calciphylaxis is a life-threatening cutaneous ulcerative/necrotic disease characterized by vascular calcification/occlusion. It occurs most commonly in end-stage kidney disease (ESKD), known as uraemic calciphylaxis (UC) but can also occur in patients with chronic kidney disease (CKD) and normal kidney function (nonuraemic calciphylaxis; NUC). There are few large series of NUC in the literature.

AIM

To compare the clinicopathological features of UC and NUC.

METHODS

We retrospectively compared the clinicopathological features of 35 patients with NUC during the period 2010-2020 with those of 53 patients with UC (control group). Cases were classified as NUC in the absence of all of the following: ESKD, significant CKD (defined as serum creatinine > 3 mg/dL or creatinine clearance < 15 mL/min) and acute kidney injury requiring kidney replacement therapy or kidney transplantation.

RESULTS

NUC represented 40% of the total cases, and there was a higher number of women (P < 0.01) and a higher median body mass index (P = 0.06) compared with the control UC group. Elevated parathyroid hormone was present in 44% of patients with NUC. Most of the tested patients were positive for lupus anticoagulants (56%). NUC biopsies showed a higher rate of extravascular calcium deposits (73% vs. 47%, P = 0.03). Dermal reactive vascular proliferation was the most common dermal change (32%).

CONCLUSIONS

NUC is more common than previously reported and shows a higher predilection for obese postmenopausal women. Undiagnosed hyperparathyroidism shows a possible association with NUC. Lupus anticoagulants were positive in most patients. NUC biopsies are more likely than UC biopsies to display extravascular calcium deposition.

Antischistosomal effects of praziquantel, its alkaline hydrolysis and sun decomposed products on experimentally S. mansoni infected albino mice. (A) Efficacy assessment based on clinicopathological findings

The antischistosomal activity of praziquantel (PZQ), its alkaline hydrolysis product (HP) and its sun-decomposed (SD) products was investigated in S. mansoni experimentally infected mice. The evaluation was made depending on the degree of clinico-pathological changes. The results obtained revealed that, PZQ, HP and the SD have induced partial suppression of worm fecundity as judged by the significant reduction in eggs per gram of faeces in comparison with the infected untreated control. The effect on tissue egg deposition in the treated groups was comparable to the infection of untrea ted control. Worm recovery showed large reduction in the number of worms for SD (47.6%) and HP (28.6%) compared to PZQ (16.6%) treated groups. So, the former two compounds have the superior antischistosomal activities. Glutamate pyruvate transominase (GPT) and glutamate oxaloacetate transaminase (GOT) concentrations were measured. The GOT values for all treated groups were significantly higher than those for the healthy control group (p=0.01). The SD group enzyme concentration was even higher than the infected untreated control. The GPT values of all groups were greater than the uninfected control and the difference was significant for the infected untreated, PZQ and the SD treated groups (p=0.05).

Lateral cervical bronchogenic cyst: an unusual cause of a lump in the neck

BACKGROUND

Congenital cysts of the neck in children are not uncommon. Most of these are thyroglossal, branchial cleft, or less commonly, thymic cysts. Bronchial cysts rarely are initially seen as a neck mass.

METHODS

Use of an illustrative case of a bronchogenic cyst initially seen as an upper lateral neck mass.

CONCLUSIONS

We emphasize that although ectopic bronchogenic cysts are rare lesions of the head and neck, especially in the upper lateral neck, they should be included in the differential diagnosis in the evaluation of congenital neck cysts.

Mortality due to schistosomiasis mansoni: a field study in Sudan

Although schistosomiasis affects 200 million persons, 20 million of whom have advanced disease, little is known about the mortality pattern in areas of endemic schistosomiasis mansoni. In an attempt to assess the mortality rates in an endemic area in Sudan, we conducted two demographic surveys in a village in the Gezira area. Clinical, sonographic, and parasitologic examinations were performed in a randomly selected sample of 25% of the population in 1987 and 1994. One of us asked each head of household about the names, sex, and age of family members. Particularly, we asked about death in the family if any, history of schistosomiasis, abdominal swelling, and hematemesis. Possible causes of death were ascertained by reviewing medical records in the village dispensary and the district hospital. There were 42 deaths in the village. Four males died of hematemesis secondary to portal fibrosis. The crude mortality rate of schistosomiasis was is 51/100,000/year. The overall schistosomiasis fatality rate per year was 1/1,000 infected persons, but was as high as 11/100/infected patients with bleeding varices. These findings showed the impact of schistosomiasis on public health in this economically important region of Sudan.

Decrease in canine proximal femoral ultimate strength and stiffness due to fatigue damage

Fractures of the proximal femur represent a significant health concern especially in the elderly. Fatigue damage and microfractures have been implicated in the etiology of hip fractures; however, the extent to which these factors are sufficient to bring about significant reductions in proximal femur strength and stiffness is unknown. This study examined the hypothesis that fatigue loading of the proximal femur results in highly correlated decreases in bone stiffness and strength through the accumulation of bone microdamage. One canine femur from each of 10 pairs was monotonically loaded to failure to determine the ultimate strength. The contralateral femur was then cyclically loaded at 50% of the ultimate load value for either 3600 cycles or until a 40% reduction in stiffness was achieved. This femur was then monotonically loaded to failure. For two additional femur pairs, the fatigued femur was histologically processed to reveal bone microdamage. In support of the hypothesis, the data demonstrated a linear relationship between strength loss and stiffness loss (Adj. R2 = 0.79, p < 0.0004) with significant decreases in residual whole bone strength (p < 0.004) following cyclic loading. In addition, damage (microcracks) in the cortical bone and broken trabeculae were observed in the neck and head region of the femur fatigued until its stiffness was reduced by 40% but not fractured subsequent to cyclic loading.

Characterization of camel leukocytes by flow cytometry and microscopic evaluation of granulocyte phagocytosis of fluorescent bacteria

Peripheral blood was obtained from four lactating camels (Camelus bactrianus) and flow cytometry was used to characterize cell populations. The ability of the granulocytes to engulf fluorescent bacteria was studied in vitro using fluorescence microscopy. Three clusters of blood cells (mononuclear cells, neutrophils and eosinophils) were identified by flow cytometry and fluorescent microscopy. Milk, on the other hand, was dominated by cell fragments and no distinct cluster formation was found. The mean yield of blood granulocytes and monocytes isolated on Ficoll gradient was 92.2 +/- 5.4% and 7.9 +/- 5.7%, respectively. Cell viability was 95%. The mean percentage of phagocytic cells was 71.8 +/- 5.9% at 10 min and increased to 97.3 +/- 0.5% at 60 min when observation was terminated. The average number of bacteria per phagocyte was 8.7 +/- 2.1 and 13.1 +/- 0.9 at 10 and 60 min incubation time.

The effectiveness of annual versus biennial mass chemotherapy in reducing morbidity due to schistosomiasis: a prospective study in Gezira-Managil, Sudan

The most serious complication of schistosomiasis is periportal fibrosis, which affects a large number of subjects in endemic areas. Population-based chemotherapy remains the most effective way of controlling this disease. In an attempt to find the best way to deliver chemotherapy to the endemic population, we compared the impact of repeated annual versus biennial mass chemotherapy on morbidity due to schistosomiasis in two villages in Gezira, Sudan. One village was given five rounds of mass chemotherapy annually in the years 1990-1994 while the other village was given three rounds of mass chemotherapy biennially from 1988 to 1994. Before treatment, these villages had similar intensity of infection and prevalence. One round of either annual or biennial treatment reduced the intensity of infection, but not prevalence or morbidity. After two rounds of annual chemotherapy, infection rates, bloody diarrhea, and fibrosis in those 20 years of age and less were significantly reduced. Two rounds of biennial chemotherapy had a similar effect on rates and bloody diarrhea; however, fibrosis was reduced only after the third round of biennial chemotherapy. Prevalence of hepatosplenomegaly increased after both treatment regimens. Reinfection was most prominent in those 5-14 years of age. These findings support the general notion that repeated chemotherapy may be needed in areas of high transmission of schistosomiasis. We recommend two rounds of annual mass chemotherapy to significantly reduce infection and morbidity.

Exposure of infants to aflatoxin M1 from mothers' breast milk in Abu Dhabi, UAE

During a survey of the occurrence of aflatoxins in mothers' breast milk carried out in Abu Dhabi, involving 445 donors at the Cornich Hospital and the Al Nehyan Clinic for Maternity and Childhood, 99.5% of samples were found to contain aflatoxin M1 at concentrations ranging from 2 pg ml-1 to 3 ng ml-1. The mothers represented a wide range of nationalities, ages and health status and the opportunity was used to seek any correlation between these factors and the concentration of aflatoxin M1 in breast milk. The protein, fat and lactose contents of milk samples were also determined and the possibility of any correlation between any of these and aflatoxin M1 was studied.

Predictors of upper gastrointestinal bleeding in patients with schistosomal periportal fibrosis

A case-control study was conducted between 1985 and 1987 in the Gezira-Managil area of central Sudan to assess the major predictors of haematemesis. Eighty-four patients who had suffered at least one attack of oesophageal bleeding and had schistosomal periportal fibrosis demonstrated by ultrasonography were compared with 173 subjects without bleeding but with ultrasonographic evidence of periportal fibrosis. A splenic longitudinal dimension of more than 11 cm, periportal fibrosis worse than grade I and varices more than grade I were independently associated with a significant risk of variceal bleeding. Age, sex, presence of a palpable liver and portal vein diameter were not associated with a significant risk of bleeding after adjustment for potential confounding variables. Factors identified in this study could be helpful in the prophylactic management of patients with complicated schistosomiasis.

Cholecystectomy with and without drainage: a prospective randomised study

The use of subhepatic intraperitoneal drains was prospectively studied in 100 patients who underwent elective cholecystectomy for symptomatic gallstones. These patients were randomised to have subhepatic drains (group A, n = 50 patients) or to have no drains (group B, n = 50 patients). There was no difference in the age or sex composition of the two groups. The patients were followed in the post-operative period (0-7 days) for evidence of fever, wound infection, septicaemia and any evidence of intra-peritoneal bile leakage. Also post operative hospital stay of patients was noted. In group A, 14 patients (28%) developed spikes of temperature of 38 degrees C or more while only 5 patients (10%) in group B developed such episodes. The difference was statistically significant between the two groups (P < 0.05). Wound infection occurred significantly more (P < 0.05) in group A (in 15 patients) as compared to group B (in 5 patients). Septicaemia occurred in 2 patients in group A and in none in group B. There was no evidence of intraperitoneal bile leakage in either group. Patients in group A tended to have longer post operative hospital stay (mean of 10.2 days) than patients in group B (mean 8.7 days); but the difference between the two groups in this respect was not significant. We conclude that subhepatic intra-peritoneal drains offered no additional advantage in elective cholecystectomy. The evidence we had pointed to their harmful effects.

Liver sonography in an area endemic for schistosomiasis haematobium

Through the use of portable ultrasonography, eight cases (2%) of periportal fibrosis were identified in a random sample of 400 subjects selected from a village with a high prevalence and morbidity due to schistosomiasis haematobium in the White Nile Province of Sudan. In contrast, 36 cases (15%) of fibrosis were seen in an area with a similar prevalence and morbidity due to schistosomiasis mansoni in the Gezira Managil region of Sudan. Although there was only one case of Schistosoma mansoni as determined by repeated stool examination of the entire sample population in the first village, the majority of those with fibrosis and age-matched controls showed serologic evidence of active S. mansoni infection. This led to the conclusion that the cases of periportal fibrosis seen in the White Nile Province are most probably due to S. mansoni rather than to S. haematobium.

Surgical treatment of chronic fissure-in-ano: a prospective randomised study

A prospective randomised study compared anal dilatation (n = 37), posterior internal sphincterotomy (n = 21) and lateral sphincterotomy (n = 20) in the surgical treatment of chronic anal fissures in 78 consecutive patients. All the operations were performed under general anaesthesia using standard techniques. Anal dilatation relieved anal pain early (immediate relief in 57% of patients; the mean pain-days +/- SD of 3.2 +/- 5.4 days). Anal fissures after this operation healed in a mean time +/- SD of 20.3 +/- 12.5 days, coming in second place to lateral sphincterotomy. Anal dilatation was followed by insignificant wound infection but its main disadvantage was a high rate of post operative anal incontinence (in 24.3% of patients). Fissurectomy and posterior internal sphincterotomy was followed by the longest period of post operative anal pain (mean +/- SD of 32.4 +/- 10 days) as compared to the other two operations. It was the least favourable operation. Lateral sphincterotomy was followed by early relief of pain (immediate relief in 95% of patients). It was not followed by wound infection. It had the quickest healing time for the fissures (a mean +/- SD of 14.7 +/- 8.7 days). It was followed by anal incontinence in only one patient. In conclusion lateral sphincterotomy was the most favourable operation and it is perhaps the operation of choice to perform in patients with chronic anal fissures needing surgical treatment.

Oesophageal varices in a region of the Sudan endemic for Schistosoma mansoni

In a field study of two villages in the Gezira, an area of the Sudan endemic for Schistosoma mansoni, liver ultrasonography was used to detect subjects with Symmers' hepatic periportal fibrosis, some of whom underwent oesophagoscopy to detect oesophageal varices. The prevalence of oesophageal varices in subjects undergoing oesophagoscopy was 54 per cent and 67 per cent respectively, occurring mainly in males aged about 30 years. The varices were usually asymptomatic. Symptomatic varices (with a positive history of haematemesis) occurred in 4 per cent and 3 per cent respectively of subjects with sonographic evidence of liver periportal fibrosis. By detecting oesophageal varices in an asymptomatic phase, hepatic ultrasonography and fibreoptic oesophagoscopy may elucidate the natural history of the varices and their response to periodic anti-schistosomal chemotherapy.

Flow cytofluorometric studies on the alteration of leukocyte populations in blood and milk during endotoxin-induced mastitis in cows

Alterations in the various leukocyte populations in milk, blood, and mammary lymph were studied by use of the flow cytometric method during acute mastitis episodes induced by endotoxin infusion (50 micrograms of lipopolysaccharide of Salmonella typhimurium SH 4809) via the teat canal. Lymph samples were collected via a semipermanent catheter from an afferent duct to the supramammary lymph node. Milk somatic cell count increased at 4 hours after infusion of endotoxin. Neutrophils were the predominant cell population for up to 59 hours after infusion. Numbers of lymphocytes and monocytes-macrophages in milk also increased after the endotoxin infusion. The total cell count in milk started to decrease during the third postinfusion day and returned to preinfusion values during the fourth day. Lymphocyte numbers remained high for about 1 week after the infusion, and lymphocytes were the predominant cell population between postinfusion days 4 and 8. Total blood leukocyte count decreased during the first 6 hours after infusion, followed by an increase until postinfusion hour 31. The proportion of neutrophils in blood increased during the first day, whereas that of lymphocytes decreased. Lymph flow rate and leukocyte numbers in lymph increased after endotoxin infusion. The proportion of neutrophils in the lymph increased during the first 6 hours, whereas that of lymphocytes decreased. After postinfusion hour 6, the inverse course of events was seen.

Influence of estradiol administration to lactating cows on bacterial growth in milk whey

Bacterial growth (E. coli) in whey was studied by turbidometric technique during estradiol benzoate administration (0.02 mg/kg of body weight/day for 12-19 days) to 13 ovariectomized cows at three stages (early, mid and late) of the 1st- and 3rd-lactations. Whey samples from cows at early stage (60-90 days) of 1st-lactation promote the growth of E. coli during the estradiol treatment. This included a significant increase in the maximum turbidity and a decrease in the generation time. Bacterial growth was inhibited in whey from cows at other stages of lactation during the hormone treatment. The degree of inhibition varied at different stages of lactation. No significant alterations in the ability of whey to support bacterial growth were observed in 3 ovariectomized cows treated with the drug vehicle (arachis oil) alone. Majority of the quarters included in the present study were bacteriologically negative throughout the study.

Influence of exogenous estradiol on the concentration of antitrypsin, albumin, N-acetyl-beta-D-glucosaminidase and somatic cells in milk of cows at various lactation stages

Estradiol benzoate (0.02 mg/kg of body weight) was injected (i.m.) daily to 13 ovariectomized cows in their first or third lactations during early (60-90 days), mid (140-200 days) and late (240-300 days) lactation. The majority of the udder quarters were free of bacteria throughout the experiment. Signs of clinical mastitis were observed after 9-19 days of treatment in cows at mid and late lactation. This was accompanied by a decrease in milk yield, an increase in milk somatic cell count (MSCC) and increases in milk concentration of antitrypsin and serum albumin (as indicator of increased permeability); and milk NAGase activity (as indicator of epithelial cell damage or release of the enzyme from phagocytes). NAGase activity was first to increase and on some occasions was not accompanied by an increased MSCC. The response was either absent (first lactation) or relatively mild (third lactation) in cows at the early stages of lactation. The intensity of the inflammatory response increased with advancing lactation stage. Generally, the response of cows in the third lactation was greater than that of cows in the first lactation at a corresponding stage of lactation. Three cows which received the control treatment with vehicle alone showed no changes in any of the parameters except a slight decrease in antitrypsin. All inflammatory indicators correlated negatively with quarter milk production; milk NAGase activity was superior in this respect (r = -0.75). All correlation coefficients were generally higher after, rather than before the hormone treatment.

Alterations in neutrophil phagocytosis and lymphocyte blastogenesis in dairy cows around parturition

The bovine blood neutrophil phagocytosis and the blood and milk lymphocyte proliferative response upon stimulation with Phytohaemagglutinin, Concanavalin A and Pokeweed mitogens was studied from 3 weeks prior to calving until 3 weeks after calving. Neutrophil phagocytosis and the total and differential blood leukocyte counts were performed by flow cytometry. A gradual increase in the percentage of phagocytized bacteria and the average number of bacteria per phagocyte was observed before calving followed by a sharp fall on the first postpartum. This was followed by a steady increase in the above parameters reaching the highest levels at two weeks postpartum. There was a gradual increase in the number of neutrophils in blood as calving approached followed by a sharp decrease after calving. The number of lymphocytes in blood dropped before calving, being at the lowest level on the day before calving. The proliferative response of blood and milk lymphocytes upon stimulation with the three mitogens was low during the week preceding parturition with the lowest value on the day before calving. The response of blood lymphocytes returned to a higher level the second week after calving while that of milk lymphocytes remained at a low level during the first and the second postpartum weeks.

Flow cytometric measurement of bovine milk neutrophil phagocytosis

A flow cytometric method for the evaluation of the phagocytic capacity of bovine milk polymorphonuclear neutrophils (PMN) is described. Milk PMN were isolated from stripping milk collected from udder quarters fitted with abraded intramammary devices (AIMD). A significant increase in the milk somatic cell count was observed in the stripping milk after the insertion of AIMD (308×10³ and 1447×l0³ cells/ml milk before respectively after the insertion of the AIMD, p < 0.001).

PMN were also isolated from blood by a discontinous gradient of Percoli. Blood and milk PMN were incubated for 15 min with FITC-labeled bacteria in a ratio of 1 PMN:20 bacteria and a final serum concentration of 10 %. The number of extracellular bacteria and the percentage of phagocytic cells were measured by a flow cytometer.

Percentage of phagocytized bacteria by milk PMN was significantly lower than that by blood PMN (p < 0.05). A smaller number of active phagocytes was present among cells isolated from milk than among cells isolated from blood. The phagocytic capacity of milk PMN reflects that of blood PMN in the same animal. A large variation in the phagocytic capacity of blood and milk PMN among animals was observed.

Gentamicin and phenytoin sieving through hollow-fiber polysulfone hemofilters

The sieving characteristics of the prototype drugs gentamicin (poorly protein bound) and phenytoin (highly protein bound) were measured in vitro using polysulfone capillary hemofilters similar to those used in clinical continuous arteriovenous hemofiltration. Plasma water, whole plasma, and whole blood were the solvent systems used with variable drug concentrations and solvent flow rates. Our results indicate that the sieving coefficients for both drugs can be accurately defined as the concentration in the ultrafiltrate divided by the concentration in the artery. This correlates with a more rigorously derived expression by Colton and Henderson (r = 0.98, P less than 0.00001 for both drugs) and avoids the necessity of measuring venous concentrations. Drug sieving in the three solvents followed expectations from known protein-binding data and was independent of solvent flow rate. For both drugs, at higher drug concentrations sieving increased in plasma, consistent with the saturation of protein-binding sites. In whole blood, sieving fell for both drugs with increasing drug concentrations, consistent with drug compartmentalization into red blood cells. Although these sieving changes with increasing drug concentrations were statistically significant, their clinical significance is doubtful. Phenytoin sieving in plasma was increased by the addition of free fatty acids, consistent with a protein-drug displacement effect. There appears to be a real, but small, effect of protein concentration polarization, protein-membrane and drug-membrane interactions on drug sieving. Our observations are consistent with the expectation that the major determinant of drug sieving is the extent of drug-protein binding.

Drug removal during continuous arteriovenous hemofiltration: theory and clinical observations

We have discussed the basic principles of pharmacokinetics and convective solute removal in the context of each other. Clinical observations appear to follow the theoretical expectations. For practical purposes plasma and plasma water are not different. In the calculation of drug sieving, venous samples do not contribute enough to warrant their extra costs. We recommend that drug removal in hemofiltration be expressed by the sieving coefficient, UF/A. Drug sieving data in humans undergoing CAVH are tabulated. Recommendations for supplemental dosing are discussed which are applicable to any clinical setting.

Flow cytometric characterization of bovine blood neutrophil phagocytosis of fluorescent bacteria and zymosan particles

A Flow Cytometric method for the evaluation of the phagocytic capacity of bovine blood neutrophils is described. The neutrophils were isolated from bovine blood by a one step discontinuous gradient of Percoll. By this technique of isolation, 90 ± 2.8 % (mean ± s) of the granulocytes in the whole blood were recovered.

Isolated neutrophils were incubated with FITC labeled S. aureus or zymosan particles in a ratio of 1:20 and 1:10, respectively, and a final serum concentration of 10 %. Phagocytosis was terminated after 15 min and the number of extracellular bacteria or zymosan particles and the percentage of phagocytic granulocytes were registered by Flow Cytometry (FCM). FCM and microscopic studies revealed that eosinophils play a minor role in the phagocytosis of bacteria. The neutrophils were the main population of the granulocytes which were actively phagocytic. Variation among cows in the ability of their blood neutrophils to phagocytize bacteria was evident.

Observations on the infectivity and fecundity of a Sudanese isolate of Schistosoma bovis in albino mice

A Sudanese isolate of Schistosoma bovis from experimentally infected sheep was found to be highly pathogenic to albino mice. Eggs were first found in the livers 42 days after exposure. The distribution of eggs in the liver and small and large intestines changed little during the course of infection. Results are compared with others using an Iranian isolate of S. bovis, which causes only a mild infection, and S. mattheei.

The pathogenesis of experimental Schistosoma bovis infections in Sudanese sheep and goats

The pathogenic effects of experimental Schistosoma bovis infection in Sudanese sheep and goats were investigated by a variety of clinical, parasitological, physiological and histopathological techniques; uninfected animals of each species were used as controls. Infected animals of both species lost or failed to gain weight and developed a haemorrhagic diarrhoea, inappetence, marked anaemia, hypoalbuminaemia, hyperglobulinaemia, hyperproteinaemia and eosinophilia. These changes first became noticeable around the time of onset of oviposition and their severity was generally related to faecal egg counts. Red cell breakdown and albumin catabolism were much higher in infected than in control animals of the same species, and it was concluded that these changes were due to haemorrhage resulting from the extrusion of large numbers of eggs through the intestinal mucosa. Although all the animals were infected with the same number of cercariae, both the number of worms reaching maturity and the tissue egg counts tended to be higher in sheep than in goats. On the other hand, goats had significantly higher faecal egg counts than sheep and it is suggested that this was the reason for the generally more severe disease in the former species.

Erythrokinetics and albumin metabolism in primary experimental Schistosoma bovis infections in Zebu calves

Red cell kinetics and albumin metabolism were studied in calves infected with either 100 or 200 Schistosoma bovis cercariae per kg body weight, by the use of 59Fe-labelled transferrin, 51Cr-labelled erythrocytes and 125I-labelled albumin; a third group of worm-free animals acted as controls. The anaemia which developed in the infected calves was shown to be due basically to an accelerated rate of red cell loss from the circulation, and became evident around the seventh week of infection, increased in severity during the following two months, and subsequently subsided. In view of its close similarity to the pattern of faecal egg excretion, it was concluded that haemorrhage into the intestine caused by the exit of eggs was the principal aetiological factor: haemolysis was excluded by the absence of both splenomegaly and hyperferraemia . Erythropoiesis was also accelerated in infected animals, but could not keep pace with the rate of red cell breakdown to which the animals were concurrently subjected. Haemodilution was involved, but not to a significant extent. The hypoalbuminaemia associated with infection was caused by an increased rate of albumin catabolism, and a plasma volume expansion, and was accompanied by marked depletion of all albumin pools, but particularly the extravascular pool. The pattern of albumin catabolism closely followed that of red cell loss, suggesting that passage of plasma as whole blood into the intestine was the basic cause of hypoalbuminaemia. Red cell losses and albumin hypercatabolism were more severe in the more heavily infected group, and although both subsided as egg counts fell, they remained evident even 1 year after infection. This may partly explain the failure of infected animals to regain the weight lost during earlier stages of disease.

Percutaneous transhepatic cholangiography in Sudan

In 16 patients percutaneous transhepatic cholangiography with a conventional needle was attempted, to establish the diagnosis of obstructive jaundice and show the nature and site of obstruction. The procedure was successful in 15 patients; only one patient subsequently had parenchymal jaundice. The conventional needle allowed bile aspiration (a mean of 22 mls in the 15 patients), which may have been an important factor in avoiding the development of post PTC septicemia. No patient had pain, bile leakage, bleeding or septicemia following the procedure. Surgery was performed as scheduled. Following the use of the conventional sheathed needle, it does not appear necessary to operate immediately.

Observations on cattle schistosomiasis in the Sudan, a study in comparative medicine. II. Experimental demonstration of naturally acquired resistance to Schistosoma bovis

Epizootiological observations on Schistosoma bovis in cattle at Kosti, Sudan, showed a significant fall in age-specific prevalence and intensity with age, based on fecal egg count. To test the possibility that this is due to acquired resistance, Kosti cattle and a control group of cattle of similiar breed and age from a nonenzootic area were experimentally challenged with 70,000 S. bovis cercariae. Clinical observations showed very clearly that the Kosti cattle were able to withstand almost completely the effects of the challenge, whereas the controls developed lethal infections. Resistance was further demonstrated by clear differences between the two groups in terms of their body weights, hematological measurements, histopathological and pathophysiological responses, and worm and egg counts. The data suggested that the main basis of the resistance was a suppression of egg production by the worms from the challenge, rather than absolute prevention of their maturation. There was also evidence of a suppression of the fecundity of worms in the naturally infected Kosti cattle.

Observations on cattle schistosomiasis in the Sudan, a study in comparative medicine. III. Field testing of an irradiated Schistosoma bovis vaccine

Previous work has shown that cattle can acquire a strong resistance to Schistosoma bovis infection following repeated natural exposure. Partial resistance to a laboratory challenge with S. bovis has also been demonstrated in calves after immunization with an irradiated schistosomular or cercarial vaccine. The aim of the present study was to see whether this type of vaccine could protect calves under the very different conditions of natural exposure to S. bovis in the field. Thirty 6- to 9-month-old calves were each immunized with 10,000 irradiated S. bovis schistosomula by intramuscular injection and 8 weeks later were released into an enzootic area along with 30 unvaccinated animals. The calves were followed up for 10 months, during which period protection was evidenced by a lower mortality rate, a slower rate of acquisition of infection, and lower fecal egg counts in the vaccinated calves. Necropsy of the survivors showed 60--70% reductions in worm and tissue egg counts of the vaccinated calves as compared to those not vaccinated.

Schistosoma bovis in calves: the development and clinical pathology of primary infections

The clinico-pathological effects of Schistosoma bovis were monitored in zebu calves for a year after exposure to 100 or 200 cercariae/kg body weight and were related to the number and reproductive activities of the parasites present. The disease was characterised by diarrhoea, weight loss or poor weight gain, anaemia, serum protein changes and eosinophilia. These changes were broadly related to the level of infection and were most prominent during the two months following patency when faecal egg counts were highest. Subsequently, the condition of most animals improved. This was associated with a marked reduction in faecal egg excretion which in turn was related to worm deaths, reduced worm fecundity and egg retention in the tissues.

Immunization of calves against Schistosoma bovis using irradiated cercariae of schistosomula of S. bovis

Fourteen 9-month-old zebu calves were immunized with 10000 irradiatedSchistosoma bovisschistosomula given in 1–3 intramuscular or subcutaneous doses, and 4 more calves were immunized with 10000 irradiated cercariae administered percutaneously in a single dose. Eight weeks after the beginning of the experiment these calves, together with four non-immunized controls were challenged percutaneously with 10000 normalS. boviscercariae/calf. Comparative clinical, parasitological, pathological and pathophysiological observations subsequently revealed significant differences between the vaccinated and non-vaccinated calves. The vaccinated calves showed significantly higher growth rates, and a superior body composition as indicated by their lower total body water content. The beneficial effects of vaccination were also shown by significantly lower faecal egg outputs in the vaccinated calves and by their lower tissue egg and adult worm counts. The reduced tissue egg counts were also reflected in the milder histopathological changes seen in the vaccinated calves. The vaccinated calves had significantly higher packed cell and circulating red blood cell volumes than the challenged controls, longer red blood cell half lives, and somewhat lower blood volumes and rates of red blood cell synthesis. No untoward clinical effects that could be attributed to vaccination were recorded. These results indicate that zebu cattle can be effectively protected againstS. bovisby vaccination with irradiated organisms. We are now evaluating this type of vaccine in a field trial in an enzootic area in the Sudan.

Quantitative determination of acetaminophen in plasma

A simple method is described for the rapid quantitative analysis of acetaminophen in plasma. The acetaminophen and its conjugates present in the plasma following drug administration are hydrolyzed with 4 N HCl to p-aminophenol. This compound is coupled with 5% vanillin reagent to form a stable yellow color whose concentration is determined spectrophotometrically at 395 nm. Application of this method to a study of three dogs treated with 650 mg of acetaminophen is described.

Simultaneous GLC determination of acetaminophen, dichloralantipyrine, and isometheptene mucate

A rapid GLC assay for acetaminophen, dichloralantipyrine, and isometheptene mucate in capsules was developed. These substances are chromatographed directly, using phenyl methyl silicone gum as the stationary phase. The standard calibration curves are linear up to 14 mg/ml, with a lower limit of sensitivity of 2 mg/ml. This method is simple and rapid and does not require derivative formation.

Spectrophotometric determination of acetaminophen and dichloralantipyrine in capsules

A rapid method for the routine determination of acetaminophen and dichloralantipyrine in capsules is reported. The determination of acetaminophen is based on the ability of its hydrolytic product, p-aminophenol, to produce an intensive yellow color with vanillin. The determination of dichloralantipyrine is based on the fact that it, as well as its major metabolite chloral hydrate, produces a blue color with quinaldine ethiodide. No interferences were encountered, and good recovery and precision data were obtained.