Factors associated with negative 99mTc-MIBI scanning in patients with primary hyperparathyroidism

OBJECTIVE

The objective was to evaluate the clinical and biological factors associated with negative ^99mTc-MIBI scanning in patients with primary hyperparathyroidism (PHPT).

MATERIAL AND METHODS

A retrospective observational study was designed in 195 patients (mean age: 59.2±13.0years; 77% woman) with PHPT (calcium: 11.3±1.1mg/dl and PTH: 218±295pg/ml) studied in endocrinology setting between 2013 and 2020. An univariate and multivariate analysis was made to evaluate the clinical and biological factors associated with negative ^99mTc-MIBI scanning.

RESULTS

50 patients (26%) with negative ^99mTc-MIBI scanning had lower PTH levels (146±98 vs. 244±334; p<0.001), adenomas with smaller sonographic dimensions (maximum diameter: 1.2±0.4 vs. 1.7±0.9cm; p=0.001 and volume: 0.36±0.43 vs. 1.7±4.1cm³; p<0.001), localized more frequently in upper parathyroid glands (37% vs. 14%; p=0.005) and associated more frequently to thyroid nodules (72% vs. 57%; p=0.045) than patients with positive scanning. 116 patients were operated and parathyroid adenomas were smaller (maximum diameter: 1.3±0.5 vs. 1.9±1.1cm; p=0.008 and volume: 0.30±0.20 vs. 1.2±1.1cm³; p<0.001), less heavy (567±282 vs. 1470±1374mg; p=0.030) and were localized more frequently in upper situation (65% vs. 16%; p<0.001) than patients with positive scanning. In the multivariate analysis an independent association between negative ^99mTc-MIBI scanning and size of removed adenoma ≤1cm (OR: 5.77; 95% CI: 1.46-22.71) and upper adenoma localization were observed (OR: 8.05; 95% IC: 2.22-29.16).

CONCLUSIONS

One in four patients studied for PHPT had a negative ^99mTc-MIBI scanning and were independent associated with size of adenoma ≤1cm and upper adenoma localization.

Simultaneous kinetic spectrophotometric determination of spironolactone and canrenone in urine using partial least-squares regression

A method is proposed for the simultaneous determination of spironolactone and canrenone in urine based on the different rates at which they react with sulphuric acid to yield a trienone. Kinetic spectrophotometric data are processed by partial least-squares (PLS) regression. The optimum sulphuric acid concentration and temperature are determined from response surfaces, using PLS methodology to relate both variables to the relative square error of prediction (RSEP, the parameter to be minimized). The relative errors made in the quantitation of each diuretic by the proposed method are less than 5% and the overall error, as RSEP, ranges from 1.06 and 1.44%.

[Study of the conpsumption of innapropiate medicaments in elder hospitalized in the Internal Medicine Service]

BACKGROUND

The elderly patients are characterized by the high degree of polymedication. This factor is the most important in the appearance of adverse effects (EAD). The study of the medicaments helps to establish which are inappropriate and therefore they must move back, diminishing of this form EAD's possibility.

PATIENTS AND METHOD

Prospective and observacional Study. Criterion of incorporation: patients of > 64 years old, hospitalized in an Internal Medicine Service. There were defined as inappropriate medicament the medicines of low therapeutic utility, them not indicated, and the inadequate ones for the elder. By means of the SPSS 11.5 program the possible variables related with the consumption were analyzed.

RESULTS

172 elders were included in the study. The average of medicines for person and day belonged to 5.34 (0-15). 52.5% was consuming an inappropriate medicament (36.6% inadequate for the elder, 15% not indicated, and 12% UTBs). The analysis multivariant associates the consumption of these medicaments with a major number of diseases (p < 0.012), to a major consumption of medicines (p < 0.001) and to the origin of the nursing residences (p < 0.001). Only the consumption of medicaments not adapted for the elder is associated with increase of EAD.

CONCLUSION

The half of the elders takes at least a medicament of unnecessary form, and the majority of these medicaments favors appearance of EAD.

Preparative HPLC resolution of the CIS cyclohexane analogs of phenylalanine

The analytical resolution of different derivatives of cis c(6)Phe (cyclohexane analogs of phenylalanine) was tested by HPLC using the mixed 10-undecenoate/3,5-dimethylphenylcarbamate of amylose bonded on allylsilica gel as the chiral stationary phase. The same chiral support has allowed the enantioseparation of racemate cis-4 on a semipreparative column (150 x 20 mm ID) with a mixture of n-hexane/2-propanol/chloroform as the mobile phase. Some 200-300 mg of the optically pure enantiomers were isolated and transformed into the N-benzyloxycarbonyl amino acids. The X-ray diffraction structure of (1R;2R)-4 is reported.

Coexpression of several types of metabotropic nucleotide receptors in single cerebellar astrocytes

We have examined the expression of mRNA for several P2Y nucleotide receptors by northern blot analysis in purified type 1 cerebellar astrocyte cultures. These results suggest that different P2Y subtypes could be responsible for ATP metabotropic calcium responses in single type 1 astrocytes. To identify these subtypes we have studied the pharmacological profile of ATP calcium responses using fura-2 microfluorimetry. All tested astrocytes responded to ATP and UTP stimulations evoking similar calcium transients. Most astrocytes also responded to 2-methylthioATP and ADP challenges. The agonist potency order was 2-methylthioATP > ADP > ATP = UTP. Cross-desensitization experiments carried out with ATP, UTP, and 2-methylthioATP showed that 2-methylthioATP and UTP interact with different receptors, P2Y(1) and P2Y(2) or P2Y(4). In a subpopulation of type 1 astrocytes, ATP prestimulation did not block UTP responses, and UDP elicited clear intracellular Ca(2+) concentration responses at very low concentrations. 2-MethylthioATP and UTP calcium responses exhibited different sensitivity to pertussis toxin and different inhibition patterns in response to P2 antagonists. The P2Y(1)-specific antagonist N:(6)-methyl-2'-deoxyadenosine 3', 5'-bisphosphate (MRS 2179) specifically blocked the 2-methylthio-ATP responses. We can conclude that all single astrocytes coexpressed at least two types of P2Y metabotropic receptors: P2Y(1) and either P2Y(2) or P2Y(4) receptors. Moreover, 30-40% of astrocytes also coexpressed specific pyrimidine receptors of the P2Y(6) subtype, highly selective for UDP coupled to pertussis-toxin insensitive G protein.

Use of partial least-squares regression for multicomponent determinations based on kinetic spectrofluorimetric data. Simultaneous determination of canrenone and spironolactone in urine

A new spectrofluorimetric method for the simultaneous determination of canrenone and spironolactone in urine is proposed. The method is based on the different rates at which the two analytes react with hot sulfuric acid to form a trienone. The kinetic spectrofluorimetric data are processed by partial least-squares regression. The effects of sulfuric acid concentration and temperature on the system under study were also evaluated and the optimum values for carring out the reaction were 50% and 50 degrees C, respectively. The method was checked by analyzing urine samples that they contained both diuretics. The accuracy and the precision of the method were tested. The relative standard errors in the quantification of each analyte in all tested samples were 3.69 and 3.59%. The proposed method was validated by comparison with a high performance liquid chromatographic method for urine samples.

Atmospheric pressure chemical ionization multi-stage mass spectrometry in the characterization of stereoisomeric synthons of cyclopropane amino acids

The mass spectrometric behaviour of (1S,2R)-, (1R,2R)-, (1R,2S)- and (1S,2S)-2-[(S)-2,2-dimethyl-1, 3-dioxolan-4-yl]-1-spiro-¿4'[2'-phenyl-5'(4'H)-oxazolone]¿ cyclopropane (2) and (1S,2R)-, (1R,2R)-, (1R,2S)- and (1S, 2S)-methyl-1-benzamido-2-[(S)-2,2-dimethyl-1, 3-dioxolan-4-yl]cyclopropanecarboxylate (3) was studied under atmospheric pressure ionization conditions and by multi-stage mass spectrometric (MS(n)) experiments performed with an ion trap. Interestingly, by using methanol as solvent, compounds 2 lead to [M + H + CH(3)OH](+) ions which, as proved by collisional experiments, exhibit the same structure of the corresponding compound 3. MS/MS of [MH](+) ions allows a clear characterization of the different stereoisomers, which give rise to specific fragmentation pathways, rationalized with respect to the structure of the neutral molecules.

Simultaneous determination of chlorthalidone and spironolactone with univariate and multivariate calibration: wavelength range selection

Chlorthalidone and spironolactone were determined simultaneously with the aid of univariate and multivariate calibration methods. Univariate calibration was performed by the zero-crossing and derivative ratio spectrum methods. Extensive spectral overlap and the scarcity of wavelengths in derivative spectra allowing one analyte to be distinguished and quantitated in the presence of the other gave rise to poor results that called for multivariate calibration. Partial least-squares regression was used in combination with a suitable method for selecting the optimum wavelength range and number of factors for analysis. The ensuing method was applied to simultaneous determination of chlorthalidone and spironolactone in a commercially available pharmaceutical preparation. The results were validated by high-performance liquid chromatography.

Potentiation of ATP calcium responses by A2B receptor stimulation and other signals coupled to Gs proteins in type-1 cerebellar astrocytes

We have studied the interaction between P1 and P2 purinoceptors in purified type-1 astrocyte cultures from postnatal days 7-8 rat cerebella using single cell microfluorimetry with fura-2. The stimulation of astrocytes with ATP elicits rapid [Ca2+]i transients showing an EC50 value of 7.9 +/- 0.3 microM. Costimulation of type-1 astrocytes with adenosine and ineffective ATP concentrations (0.1 or 1 microM) evoked [Ca2+]i transients that correspond to 60% of the maximal ATP response. NECA (5'-N-ethylcarboxamidoadenosine) was the only agonist that mimicked the adenosine effect and showed an EC50 value of 0.17 +/- 0.01 microM. This value was identical to that obtained for the cAMP production stimulation, indicating that A2B receptors coupled to adenylate cyclase activation were involved. The presence of A2B adenosine receptors was also confirmed by immocytochemistry experiments. When astrocytes were costimulated with isoproterenol and ineffective ATP concentrations similar [Ca2+]i transients were observed. The treatment of astrocytes with cholera toxin potentiated ATP calcium signals, lowering the EC50 value for ATP to 1.5 +/- 0.2 microM. However, the pretreatment of cells with forskolin or a permeable cAMP analogue had no effect on ATP calcium responses. These results indicated that the potentiation mechanism was elicited before the adenylate cyclase activation. We could conclude that in type-1 astrocytes, the activation of A2B adenosine receptors or other signals positively coupled to adenylate cyclase stimulation strongly potentiate metabotropic calcium responses to ATP. The potentiation was parallel but independent on cAMP accumulation suggesting the involvement of beta gamma subunits released after Gs stimulation.

Potentiation of adenosine 5'-triphosphate calcium responses by diadenosine pentaphosphate in individual rat cerebellar astrocytes

The calcium responses induced by adenosine 5'-triphosphate (ATP) were examined in single cerebellar type 1 astrocytes by fura-2 microfluorometry. ATP elicited fast and transient increases of intracellular calcium concentration ([Ca2+]i) even in the absence of extracellular calcium, indicating the involvement of metabotropic purinoceptors. The co-stimulation with P1P5-di(adenosine-5')pentaphosphate (Ap5A; 0.1 microM) potentiated ATP-metabotropic calcium responses. After this preincubation ineffective concentrations of ATP triggered 40% of maximal response. Co-stimulation with Ap5A and ATP was mandatory. The potentiated response to ATP was also independent of extracellular Ca2+ and was maintained for long periods of time (h). These results show a relevant interaction of purinoceptors that may imply a novel mechanism of action for diadenosine polyphosphates.

Simultaneous determination of diazepam and pyridoxine in synthetic mixtures and pharmaceutical formulations using graphical and multivariate calibration-prediction methods

Several methods are reported for the simultaneous determination of diazepam and pyridoxine: two graphical methods (zero-crossing and derivative quotient spectra); and two numerical methods (multiple linear regression and partial least-squares regression). The methods have been applied in the concentration ranges 1.4-4.0 micrograms ml-1 diazepam and 4.0-12.0 micrograms ml-1 pyridoxine. The accuracy and precision of the methods have been determined and they have been validated by analysing synthetic mixtures containing the two drugs in variable proportions. The methods were also applied to the determination of diazepam and pyridoxine in pharmaceutical preparations. The analytical results were quite good in all cases.

[Embryonal fatty tumors. Lipoblastoma-lipoblastomatosis]

The authors present four cases. The first case is a diaphragmatic-mediastinal, the second one is a cervical-mediastinal one, the third case has a buttock, the last one is a case of hip-thigh. Their ages are one, eight and three years old and the fourth case is seven days old. They appear in axilla, neck, thoracic wall and fat prevertebral tissue, in below three year old children. Despite their benignity, the tumors grow very fast. The complete extirpation is fundamental to avoid relapses, which are presented approximately in a 15 for 100 of the cases. Mutilations are not necessary, since it is a benign tumor. Finally, the authors amply review the literature. They differentiate the concepts of lipoma, hibernoma and lipoblastoma.

[Total parenteral nutrition. A 1-year experience with 96 patients]

In 1987, ninety-six surgical patients, of whom 44 were premature or newborn babies and 52 were infants or older children, received total parenteral nutrition (T.P.N.) at our hospital. A peripheral venous line was utilized on forty patients in the first group and only on 9 in the second group. The excellent results yielded by T.P.N. are self-evident from the low mortality showed by these patients. Thirty-three out of the 44 neonates and premature infants with serious surgical problems survived, being noteworthy the occurrence of just 3 deaths within a series of 13 necrotizing enterocolitis. In the series of 52 infants and older children, composed of 13 digestive patients (with 5 liver transplants), 6 tumoral, 9 neurologic, 4 renal (2 transplantations), 18 cardiac, 1 thoracic and 1 burnt, only 9 patients died. The average duration of T.P.N. was 10 days in the group of premature and newborn infants and 6 days for the nursing infants and older children, save for the 8 patients in whom the treatment had to be prolonged for a few months. We conclude that T.P.N., when applied in time and of short duration should entail no risk at all. In neonate and premature infant a peripheral vein shall be the route of choice. In the nursing infant and older child a central venous line is preferable, if possible the superior vena cava or its major tributary veins.

[Fistula of the pyriform sinus. Report of 2 cases]

The authors present two patients of 8 and 11 years of age that presented a left sided piriform sinus fistula diagnosed by esophagram and surgically treated in our centre. One had been operated previously with a diagnosis of relapsing thyroglossal quist on five occasions. The piriform sinus fistula is a recently recognised entity as cause of thyroiditis and suppurative cervical infections in the pediatric age. Communicated for the first time in the literature in 1957 by Japanese authors, it was not until 1973 that Tucker published for the first time in English a case of recurrent cervical abscess caused by a fistula initiated in the piriform sinus. Until now very few cases have been published. The majority of authors consider it to be an embryological residue of the third or fourth pharyngeal pouch. The key to diagnosis is to bear it in mind whenever a patient presents suppurative thyroiditis or repetitive cervical infections, principally of the left side. An esophagram is necessary to demonstrate the course of the fistula. In cases of thyroiditis a thyroidal gammagraphy will allow vision of a cold zone in the upper third of the affected lobe. Treatment consists of total extirpation of the fistula and affected portion of the thyroidal lobe, once the infection has been solutioned. Before intervention it is important to collocate a tube in the fistula's course by means of a direct microlaryngoscopy which will serve as guide and allow the injection of methylene blue.

[Bolande's tumor: significance of its early diagnosis and treatment]

Four patients diagnosed of having a tumor of Bolande and treated at our institution in the past ten years are presented. In two of them, early diagnosis was aided by prenatal echographic techniques; the other two diagnoses were suspected ar three and ten days of age because of an abdominal mass. The four of them underwent a complete study which included: a plain abdominal film, an ultrasound scan and an intravenous urogram; the last three patients were also surveyed by a CT scan of the abdomen. Surgery was undertaken early on all the patients, the time of operation being in every instance within the first month of life. A laparotomy was performed and, once the contralateral kidney had been carefully examined, a nephroureterectomy was implemented, having been able to preserve in all the cases the suprarenal gland in view of the benign nature of the tumor. A histologic study confirmed the diagnosis and revealed the complete delimitation of the tumor by the renal capsule. The authors underscore the importance of this tumor's suspicion in the face of any solid renal mass detected by prenatal echography or in the neonatal period, since early diagnosis and treatment are imperative in order to prevent the ensuing complications in the rare and unfortunate cases that show a malignant tumoral trend.

[Surgical approach in persistent neonatal pneumothorax]

837 neonates required mechanical ventilation at the Neonatal Intensive Unit in the last five years. 136 of them developed tension pneumothorax. Authors report our experience in these patients, who underwent next protocol: 1. Early diagnosis. 2. Underwater-seal drainage. 3. Suction drainage. 4. Selective intubation of contralateral bronchus. 5. Surgical closure. We explain step to step the protocol, specially in the 15 neonates who needed surgery. In such cases, surgical survival was 100%, in the postoperative phase 93% and total survival reached 78.5%. Therefore, we recommend surgery closure in patients who maintain pulmonary fistula in spite of an aggressive conservative treatment.

[Intestinal diversions in the treatment of Hirschsprung's disease]

Forty six enterostomies performed among one hundred and thirty one patients with Hirschsprung's diseases are reviewed. The advantages and disadvantages of the different types of intestinal diversions are considered. We conclude that the best option is to make a terminal enterostomy just proximal to the aganglionic gut.