Seroprevalence of Toxocara at Tra Vinh University Hospital in Vietnam

OBJECTIVE

The study aims to assess the seroprevalence of Toxocariasis and its associated risk factors among individuals attending the outpatient department at Tra Vinh University Hospital, Vietnam, in 2022.

SUBJECTS AND METHODS

A cross-sectional survey was conducted among outpatients of Tra Vinh University Hospital. Toxocariasis diagnosis was based on the Enzyme-Linked Immunosorbent Assay (ELISA) performed at the hospital's laboratory department. We assessed the seroprevalence of Toxocariasis and evaluated associated risk factors, including demographics and certain behaviors.

RESULTS

Of the 249 participants surveyed, 165 tested positive for Toxocariasis, yielding a seroprevalence of 66.3% (95% CI: 60.4-72.1). Multivariate analysis revealed that age groups up to 30 and 30-60 years had higher odds of Toxocariasis infection, with adjusted odds ratios (aOR) of 2.52 (95% CI: 1.04-6.11) and 3.21 (95% CI: 1.44-7.15) respectively. Additionally, individuals residing in rural areas and those in contact with dogs or cats had increased risks, with aORs of 2.21 (95% CI: 1.21-4.01) and 2.04 (95% CI: 1.10-3.79), respectively. Notably, hand washing before eating emerged as a protective factor against Toxocariasis, presenting an aOR of 0.38 (95% CI: 0.19-0.76).

CONCLUSIONS

Our findings underscore a significant seroprevalence (66.3%) of Toxocara spp. among outpatients at Tra Vinh University Hospital. Proactive measures, including hand hygiene before meals and after pet interactions, are advocated. There is a pronounced need for community-level epidemiological surveillance for human Toxocariasis.

Effect of Sevoflurane and Isoflurane on Post-Anaesthesia Cognitive Dysfunction in Normal and Type II Diabetic Rats

Both animal and human studies have documented cognitive and behavioural impairment after exposure to inhalational anaesthetics. Therefore, the current study was designed to demonstrate if the anaesthetics isoflurane and Sevoflurane can result in postoperative cognition dysfunction in normal and diabetic rats. Sixty male Wister rats aged 12 weeks were divided into 6 groups (n=10); group C (standard control), group CD (diabetic control), group S (sevoflurane anaesthesia), group I (isoflurane anaesthesia), group SD (diabetic sevoflurane anaesthesia) group ID (diabetic isoflurane anaesthesia). Animals were anaesthetized with either 2. 5% sevoflurane or 1.5% isoflurane, respectively, for 2h. 1 week later, animals were undergone cognitive tests in (a Morris water maze, T maze and open field arena), the animals were sacrificed, and hippocampus homogenates were studied for caspase 3 activity by western blot assay. Induction of type II diabetes in CD, SD and ID groups was carried out by feeding on a high-fat diet for 8 weeks before the start of the experiment. During the fourth week, Type II diabetes was induced in the experimental group by a single IP injection of 30 mg/kg STZ. Control (normal and diabetic) rats showed no change in long-term/reference memory, non-spatial working memory, exploratory activity or caspase 3 expression in the hippocampus homogenate. Anaesthesia with isoflurane in normoglycemic rats resulted in a significant decline in long-term/reference memory and non-spatial working memory, while exploratory activity and caspase 3 expressions in hippocampus homogenate showed no change to normal control rats. Both isoflurane and Sevoflurane in diabetic rats demonstrated a decline in long-term/reference memory, non-spatial working memory, exploratory activity and caspase 3 expression in hippocampus homogenate compared with normal control rats. Diabetes revealed significant post-anaesthesia cognitive dysfunction after anaesthesia with Sevoflurane or isoflurane in all the studied domains compared to standard control or diabetic control.

Association study of HIF-1α rs11549465 and VEGF rs3025039 genetic variants with diabetic retinopathy in Egyptian patients: crosslinks with angiogenic, inflammatory, and anti-inflammatory markers

Background

Genetic factors are implicated in the progression of DR—a global cause of blindness. Hence, the current work investigated the association of HIF-1α rs11549465 and VEGF rs3025039 genetic variants with the different stages of retinopathy among T2DM Egyptian patients. The crosslinks of these variants were explored with angiogenesis (VEGF), inflammation (AGEP and VCAM-1), and anti-inflammation (CTRP3) markers. Two hundred eighty-eight subjects were recruited in this study: 72 served as controls and 216 were having T2DM and were divided into diabetics without retinopathy (DWR), diabetics with non-proliferative retinopathy (NPDR), and diabetics with proliferative retinopathy (PDR). The genetic variants were analyzed using PCR-RFLP and their associations with NPDR and PDR were statistically tested. The circulating levels of AGEP, VCAM-1, HIF-1α, VEGF, and CTRP3 were assayed followed by analyzing their associations statistically with the studied variants.

Results

Only HIF-1α rs11549465 genetic variant (recessive model) was significantly associated with the development of NPDR among T2DM patients (p < 0.025) with a significant correlation with the circulating HIF-1α level (p < 0.0001). However, this variant was not associated with PDR progression. Neither HIF-1α rs11549465 nor VEGF rs3025039 genetic variants were associated with the PDR progression. The circulating AGEP, VCAM-1, HIF-1α, and VEGF were significantly elevated (p < 0.0001) while the CTRP3 was significantly decreased (p < 0.0001) in NPDR and PDR groups. The HIF-1α rs11549465 CT and/or TT genotype carriers were significantly associated with AGEP and VCAM-1 levels in the NPDR group, while it showed a significant association with the CTRP3 level in the PDR group. The VEGF rs3025039 TT genotype carriers showed only a significant association with the CTRP3 level in the PDR group.

Conclusion

The significant association of HIF-1α rs11549465 other than VEGF rs3025039 with the initiation of NPDR in T2DM Egyptian patients might protect them from progression to the proliferative stage via elevating circulating HIF-1α. However, this protective role was not enough to prevent the development of NPDR because of enhancing angiogenesis and inflammation together with suppressing anti-inflammation. The non-significant association of HIF-1α rs11549465 with PDR among T2DM patients could not make this variant a risk factor for PDR progression.

Arthroscopic medial meniscus trimming or repair under nerve blocks: Which nerves should be blocked?

Background:

This study aimed to determine the role of the sciatic and obturator nerve blocks (in addition to femoral block) in providing painless arthroscopic medial meniscus trimming/repair.

Materials and Methods:

One hundred and twenty patients with medial meniscus tear, who had been scheduled to knee arthroscopy, were planned to be included in this controlled prospective double-blind study. The patients were randomly allocated into three equal groups; FSO, FS, and FO. The femoral, sciatic, and obturator nerves were blocked in FSO groups. The femoral and sciatic nerves were blocked in FS group, while the femoral and obturator nerves were blocked in FO group. Intraoperative pain and its causative surgical maneuver were recorded.

Results:

All the patients (n = 7, 100%) in FO group had intraoperative pain. The research was terminated in this group but completed in FS and FSO groups (40 patients each). During valgus positioning of the knee for surgical management of the medial meniscus tear, the patients in FS group experienced pain more frequently than those in FSO group (P = 0.005).

Conclusion:

Adding a sciatic nerve block to the femoral nerve block is important for painless knee arthroscopy. Further adding of an obturator nerve block may be needed when a valgus knee position is required to manage the medial meniscus tear.

Lidocaine use in ultrasound-guided femoral nerve block: what is the minimum effective anaesthetic concentration (MEAC90)?

BACKGROUND

This study aimed to estimate the minimum effective anaesthetic concentrations of lidocaine required to block the femoral nerve under ultrasound (US) guidance in 90% (MEAC90) of patients.

METHODS

A minimum of 45 patients who had undergone knee arthroscopy were included in this observational study. All the patients received US-guided sciatic, obturator, and femoral nerve blocks. The femoral nerve block was performed using 15 ml of lidocaine. The lidocaine concentration given to a patient was determined by the response of the previous patient (a biased-coin design up-down sequential method). If a patient had a negative response, the lidocaine concentration was increased by 0.1% w/v in the next patient. If a patient had a positive response, the next patient was randomized to receive the same lidocaine concentration (with a probability of 0.89) or to receive a concentration 0.1% w/v less (with a probability of 0.11). A positive response was defined as complete sensory and motor block. The patients' responses were analysed to calculate the mean MEAC90.

RESULTS

Fifty-two patients were required to complete the study; 45 had a positive response and seven had a negative response. The mean MEAC90 was estimated to be 0.93% w/v [95% confidence interval (CI), 0.8-1.03%]. Lidocaine 0.93% w/v was estimated to produce a successful block in 89% (95% CI, 78-100%) of patients.

CONCLUSIONS

Perineural injection of 15 ml of lidocaine 0.93% w/v under US guidance could provide successful femoral nerve block in 90% of patients.

Trauma epidemiology and outcome in a developing country: perspectives from a university teaching hospital in Beirut

This study aims at evaluating trauma care at the American University of Beirut Medical Centre (AUB-MC) and comparing it to the norms established by the Major Trauma Outcome Study (MTOS). From January 2001 until January 2003, data necessary to calculate probability of survival using the Trauma Injury Severity Score methodology were collected. M, W, Z, Ws and Zs statistics were calculated to compare outcome at AUB-MC to the MTOS dataset. A total of 873 patients were included in the study. W statistics was calculated at 0.35 with Z score for the overall sample of 0.081 indicating that there was no statistically significant difference in survival between this group and the MTOS group. In a developing country a hospital achieves trauma outcomes similar to the MTOS dataset. Further studies looking at trauma care in Lebanon as a whole are needed.

Five-year surveillance of acute flaccid paralysis in Malaysia

OBJECTIVE

The nation-wide surveillance for acute flaccid paralysis (AFP) was implemented in Malaysia in 1995 and further intensified in 1996 as part of the World Health Organization's (WHO) certification process for polio eradication in the Western Pacific Region. Clinical data on AFP cases during a 5-year surveillance period from 1997 to 2001 were compiled and analysed.

RESULTS

Based on 517 cases of AFP reported during this 5-year period, the overall rate of AFP was 1.2 per 100 000 children below 15 years old. The major clinical diagnosis associated with AFP were Guillain-Barre syndrome (30.2%), central nervous system infection (16.2%), transverse myelitis (10.6%) non-polio enterovirus infection (6.2%), and hypokalaemic paralysis (5.2%). This unusual pattern with an excess of CNS infection and non-polio enterovirus infection was attributed to the outbreak of enterovirus 71 infection nation-wide in 1997. According to the WHO virological classification, there was no case of poliomyelitis due to wild poliovirus. Three cases were 'polio compatible', there were no cases of vaccine-associated paralytic polio (VAPP), while 62 cases (12.0%) were merely classified as 'non-polio AFP'.

CONCLUSION

Overall, these data suggest the absence of circulation of wild poliovirus in Malaysia from 1997 to 2001. The pattern of AFP in this study is different from other published reports.

Detection of Vibrio cholerae 01 from aquatic environment in Sarawak

The detection of Vibrio cholerae 01 from the aquatic environment of Daro and Bintulu in Sarawak was carried out following an outbreak of cholera. Conventional culture methods and detection of ctx gene by polymerase chain reaction technique were carried out on 80 water samples. Only one sample was positive by culture methods while 8 were positive by PCR. DNA finger printing by pulsed-field gel electrophoresis showed that the clinical isolates in Daro and Bintulu were genetically identical while the environmental isolate was closely related. Recovery of Vibrio cholerae by culture method is poor and newer methods of detection should be developed.

The treatment of pulled elbow: a prospective randomized study

To evaluate the effectiveness in decreasing recurrence of cast application after manual reduction of pulled elbow. Sixty-four children with pulled elbow were randomized into two treatment groups: Group A underwent manipulative reduction followed by splinting the elbow in a flexed and supinated position for 2 days; group B underwent manipulative reduction only. Both groups were examined 2, 5, and 10 days later. None of the 33 patients in group A had a pulled elbow at follow-up. Four (13%) of 31 patients in group B had a pulled elbow 2-5 days later. Immobilizing the elbow for 2 days after manipulative reduction improves the success of treatment of a pulled elbow.

Laparoscopic inguinal hernia repair

Open hernia repair is associated with significant postoperative pain and disability resulting in delayed return to full activity. Laparoscopic hernia repair has been advocated as the procedure that combines the benefit of tension-free repair with the preservation of the basic anatomy of the inguinal area. We present our experience with 803 laparoscopic hernia repairs in 517 patients over a period of 66 months (August 92 to February 98). The effects of the learning curve and the refinement of the technique had their impact on earlier results and complications. However, with more experience we found that the laparoscopic preperitoneal approach is safe and efficacious. There was no mortality. Most patients (85%) were discharged home within 24 h of the procedure and returned to full activity within 10 days. Patient satisfaction was excellent. The complication rate decreased and operative time was reduced with experience. This procedure is clearly indicated in patients who have recurrent or bilateral hernias. It is associated with shorter convalescence and a quick return to work.

Bupivacaine local injection in anorectal surgery

A retrospective study of 46 patients who received bupivacaine local injections after hemorrhoidectomy were compared to a matching group of 46 patients of similar age and sex distribution who underwent the same operation. Pain medications requirement on the same day of operation and on subsequent days were measured and found to be the same in both groups. The incidence of urinary retention was equal in both groups. However, the group receiving bupivacaine had a shorter hospital stay. In this respect, local injection of bupivacaine after hemorrhoidectomy may have a role in making patients more comfortable and shortening hospital stay.

Straight pin aspiration in young women

Straight pins are used extensively for securing facial scarves in women and girls in the Middle East. Accidental aspiration often results in the pin lodging in the segmental bronchus with the sharp end pointing cephalad. Flexible bronchoscopy is superior to rigid bronchoscopy in retrieving these pins. We report on five cases successfully treated by fiberoptic bronchoscopy under general anesthesia.

Surgical therapy for pulmonary hydatidosis

Surgical treatment of pulmonary hydatidosis varies from one country to another. Whereas some reports describe marsupialization of the residual cavity others favor capitonnage (imbrication) to decrease complications and hospital stay. Post operative complications and hospital stay were compared in a retrospective study of 53 patients treated surgically at the American University Hospital over a period of 10 years. Forty eight cysts were treated by evacuation after chemical sterilization. Fifteen were marsupialized and 33 were imbricated. Five were excised with lung parenchyma, 5 were delivered intact and one cyst was treated by lobectomy. There was no postoperative mortality. There was no statistical difference in the hospital stay or the complication rate between the marsupialized and imbricated cases. Both imbrication and marsupialization are equally effective methods of treatment of pulmonary hydatid cysts. Anatomic resection is rarely required.

Survey of availability of iodine-enriched salt in Sarawak

Three hundred and forty five salt samples were randomly taken from 106 sources where iodised salts were supplied or put for sale in all areas gazetted as endemic goitre areas in Sarawak. The samples were analysed for the presence of iodine. In areas in Sibu, Sarikei and Kapit Divisions, 53-70% of salt put for sale were iodised while in the other 6 Divisions, it was less than 27%. As iodisation of salt is an interventive measure in addressing the goitre problem in the State, regular monitoring of iodisation facilities and iodine content of iodised salt in the affected areas is important to ensure the effectiveness of the programme.

Successful delayed repair of a complete transection of the right mainstem bronchus in a five-year-old girl: case report

Bronchial transection of a main bronchus is usually recognized and repaired immediately after injury. Delayed repair is uncommon, especially in pediatric patients. We report a case of delayed repair of a transected right mainstem bronchus in a 5-year-old girl, 3 years after the initial injury. The transected lung re-expanded immediately and showed continued growth 3 years later.

Involvement of capsaicin-sensitive primary afferent fibers in regulation of jejunal alanine absorption

Capsaicin-sensitive primary afferent fibers (CSPA) in the small intestine regulate many functions through the release of peptides and neurotransmitters. This study was undertaken to assess the role of CSPA in the regulation of jejunal alanine absorption in the rat. In a series of in vivo experiments, the effects of the sensory neurotoxin capsaicin on small intestinal alanine absorption were evaluated. In vitro experiments were also done to study its effects on alanine uptake by isolated jejunal strips and mucosal scrapings. Jejunal alanine absorption was reduced by 27% when capsaicin (160 and 800 microM) was perfused intraluminally and by 21% when it was applied topically to the cervical vagi. On the other hand, bilateral cervical vagotomy and reversible block of vagal CSPA increased alanine absorption by 29 and 41%, respectively. In vitro, capsaicin reduced alanine uptake by intestinal strips in a dose-dependent manner. Maximal inhibition (36.5%) occurred at 400 microM with the mean ineffective concentration at 87 microM. Alanine uptake by jejunal mucosal scrapings, however, was decreased only by 6.7% when incubated with 1,600 microM capsaicin. These data suggest that vagal CSPA exerts a tonic inhibitory effect on alanine absorption and that capsaicin's inhibitory effect on alanine absorption is mediated largely by the capsaicin-sensitive afferent fibers.

Defective collagen metabolism in Saudi patients with hernia

Fibroblastic cell cultures were derived from the hernial sac and some of the surrounding muscles (rectus sheath, internal oblique, and/or cremasteric muscle) of 130 Saudi patients with different types of herniation, and from 21 control subjects. The rates of cell proliferation were studied for 39 days. Results suggested decreased rates of proliferation of cells derived from patients compared to controls. In vitro studies of the rates of incorporation of 14C proline into the muscle biopsies revealed decreased rates of label incorporation in the samples derived from patients compared to controls. However, no differences were detected between rates of collagenase activities of the biopsies obtained from patients compared to those of controls. These findings suggest that collagen synthesis is probably defective in the studied group of Saudi patients with hernia.

Palmitic acid kinetics in fasting, traumatized patients

The contribution of free fatty acid oxidation to the elevation in energy expenditure after trauma has not been well characterized. Six control subjects and six traumatized patients were fasted for 48 hours and given a primed continuous infusion of (1-14C)palmitate to measure plasma palmitate and total free fatty acid kinetics. Traumatized patients had greater urinary nitrogen losses (20.8 vs. 9.3 g N per day) and a significantly greater ratio of measured to predicted resting energy expenditure (+36% vs. -6%) compared with controls. Individual and total plasma free fatty acid concentrations were similar for the two groups. The turnover and oxidation of plasma palmitate and total free fatty acids were not changed by multiple trauma. These results demonstrated that plasma free fatty acids and palmitate do not contribute to increased energy expenditure following trauma.

Fatty acid profiles of sebaceous triglycerides by capillary gas chromatography with mass-selective detection

Fatty acid methyl esters prepared from the triglyceride fraction of skin surface lipids from six adult human males were chromatographed on a 50-m fused-silica column coated with the highly polar cyanopropylpolysiloxane phase. This permitted the resolution of double-bond positional and geometric isomers. By means of mass-selective detection, 33 saturated and 14 unsaturated fatty acid chain types were analysed. Interpretation of the mass spectra combined with precise calculation of equivalent chain length values permitted the identification of 22 saturated and all of the unsaturated chain types. Quantification by integration of total-ion and selected-ion chromatograms revealed marked variation in the triglyceride fatty acid composition between different subjects. The greatest variation was observed in the concentrations of even-carbon-numbered iso-branched acids, which ranged from 1.5 to 11% of the saturated and from 1.9 to 12.7% of the monounsaturated acids. The anteiso chain structures constituted 4-9% of the saturated and 3-6% of the unsaturated members. Fatty acids with 4-methyl branch showed the least variation, in the range 5.7-7.4%. Other methyl-branched acids made up 4-10% of the saturated group, but were not detected in the unsaturated acids fraction. Two 18:1 fatty acids were identified (a delta 8 and a delta 9), which possibly have different anatomical origins. Similarly, two 18:2 fatty acids (linoleic and a 2,3-dimethyl derivative) were identified. A 2-methyl C17 acid, probably of bacterial origin, was detected.

Iliopsoas hypertrophy mimicking acute abdomen in a bodybuilder

Marked hypertrophy of the psoas muscle in a bodybuilder produced a unilateral extrinsic mass effect upon the medial cecum and adjacent small bowel. The patient had presented with right lower quadrant pain and leukocytosis. Routine contrast studies of the abdomen were misleading, but a computed tomogram suggested the correct diagnosis.

Variability in the composition of human skin surface lipids in tropical climates

Skin surface lipid samples were collected by the hexane sponge technique from the foreheads of 180 male and 131 female Saudi subjects living in the Jeddah-Makkah area (summer temperatures up to 47 degrees C). The lipid samples were analyzed by densitometric thin layer chromatography. Seven major lipid classes were determined. The percentages for squalene, cholesterol esters, wax esters, triglycerides, free fatty acids, cholesterol and diglycerides were determined. When these parameters were compared to the corresponding values reported for subjects living in the much cooler climates of Europe and N. America, most of the values for Saudi females were found very similar to the values of these subjects, while for Saudi males squalene and wax esters were 2.8-5.1% higher and the triglycerides/free fatty acids were 3-5% lower. The possible reasons for the observed variability between both sexes, their relation to European and N. American subjects, as well as the role of hot climates in inducing these variations are discussed.

Pediatric pancreatic pseudocyst associated with cholelithiasis

Pseudocyst of the pancreas is an uncommon problem in pediatric practice, and when related to gallstones, it is rare. A 13-year-old male adolescent with pseudocyst of the pancreas associated with cholelithiasis and chronic cholecystitis presented with a peculiar clinical picture. The etiology, pathophysiology, diagnosis, and treatment of pancreatic pseudocysts and gallstone pancreatitis in children are discussed.

Anatomic characteristics of the pancreatic arteries. Radiologic observations and their clinical significance

Major complications of operations that remove or transplant a portion of the pancreas appear related to the arterial blood supply. Hemorrhage is a result of inadequate control of the appropriate principal arteries, and ischemia and its consequences occur when the arterial blood supply to portions of preserved pancreas has been inadvertently interrupted. This radiographic study of the principal arteries of the pancreas demonstrates that these vessels may be visualized and their origin determined in the vast majority of cases. The application of data gained from preoperative arteriography can potentially decrease the incidence of major complications associated with removal or transplantation of portions of the pancreas.

Surgical treatment of atypical mycobacterial lymphadenitis in children

A retrospective study was done on 38 patients with atypical mycobacterial lymphadenitis who underwent surgical intervention at The Children's Hospital, Denver, between the years 1953 and 1983. One group consisting of 18 patients had incision and drainage of the abscess or biopsy only. Sixteen of these patients developed a draining sinus or recurrent disease within a few months despite the use of antituberculous drugs or antibiotics. The other group, consisting of 20 patients, were treated initially by total excision of the inflammatory mass with no persistence or recurrence. The groups were found to be comparable with respect to age, sex, race, duration of disease and size and site of the lymph node involved. We recommend total excision of the lesion without antituberculous medications as the first choice of treatment.

Acute torsion of the gallbladder in a 100-year-old female patient

Torsion of the gallbladder is rare. However, the surgeon should be aware of it and that unusual presentations in the elderly make early diagnosis very difficult. A 100-year-old white female presented with right-sided abdominal pain and was found to have acute torsion of the gallbladder. The clinical picture, diagnostic tests, and operative findings are outlined. Serial evaluations of the patient's condition and a high index of suspicion are essential elements for prompt recognition and early surgical management.

Spectrophotometric determination of ephedrine hydrochloride and phenylephrine hydrochloride

A method is described for quantitative determination of the sympathomimetic amines ephedrine HCl and phenylephrine HCl. The method is based on the interaction of N-alkylvinylamine formed from the condensation of the free secondary amine group and acetaldehyde with chloranil to give a vinylamino-substituted quinone. The colored product for ephedrine HCl and phenylephrine HCl exhibits 2 maxima at about 320 and 680 nm. All variables were studied to optimize reaction conditions. The relationship between absorbance and concentration was linear within 1-25 micrograms/mL under the conditions studied for both drugs at both wavelengths. The method has been applied to the analysis of some pharmaceutical formulations including tablets and eye drops with good recoveries (98.75-100.4%).

The thymus and myasthenia gravis

The relationship between the thymus and the pathogenesis of myasthenia gravis is reviewed. Ten cases of myasthenia gravis who underwent thymectomy at the American University Hospital of Beirut are presented. The various pathologic features of the thymus encountered in myasthenia gravis are presented. The indications for thymectomy and the results of surgical intervention on the course of the disease are reviewed. The conclusion is made that thymectomy should be done on all patients with generalized myasthenia gravis irrespective of age, sex, duration of disease or pathological features of the thymus.

C-NMR spectroscopy of tropane alkaloids

The natural abundance 13C-NMR spectra of tropine, atropine, scopolamine, cocaine, atropine methonitrate, and dl-tropic acid were determined at 22.63 MHz. With the aid of proton decoupling techiniques and by comparison with analogous simpler compounds, it was possible to make self-consistent and unambiquous assignments of all carbon resonances for these alkaloids. Some important chemical shift trends were observed and should be useful in the identification of similar systems.

Analysis of alkaloid mixtures by charge-transfer complexation

Binary mixtures of weak and strong UV-absorbing alkaloids were analyzed by a charge-transfer spectrophotometric method, utilizing iodine in ethylene dichloride as the acceptor. In the uncomplexed form, the strong absorbing alkaloid (papaverine, quinine, ergotamine, or reserpine) was measured at a wavelength where there was no interference from weak absorbers (at 335, 332, 315, or 300 nm, respectively). The weak absorbing alkaloid (ephedrine, codeine, atropine, or homatropine methylbromide) was determined by computing its contribution to the total charge-transfer band at 295 nm where absorbance was linearly additive for mixtures. The greater increase in the original epsilon-values of the weak absorbers upon complexation with iodine relative to the corresponding increase in the epsilon-values of the strong absorbers led to good recoveries even at the low dose ratios of the weakly absorbing, and often more potent, alkaloids.

Spectrophotometric analysis of alkaloids with picrolonic acid

The spectroscopic characteristics of the interaction of alkaloids with picrolonic acid were studied. In solvents of low and intermediate polarity, the presence of alkaloids caused a red shift of the 322 nm band of nonionized picrolonic acid to 355 nm, corresponding to the anionic resonance band. There was also a considerable increase in absorptivity, which was dependent on both the basicity (pKa) and molar concentration of the alkaloid present. Arylamines, aromatic N-heterocycles, and alkaloids lacking an aliphatic amine moiety did not show observable shifts. The interaction was developed into a spectrophotometric assay for the following alkaloids in pharmaceutical preparations: atropine, ephedrine, codeine, emetine, quinine, and strychnine. The method is sensitive to 2 mug alkaloid/ml, with an accuracy of not equal to 1.5% and a standard deviation of not equal to 1.05 - 1.31%.