Pharmacokinetic study of the new sulfamethopyrazine-trimethoprim combination (kelfiprim) in renal insufficiency

The combination of trimethoprim (TMP) and sulfamethopyrazine (SMP) has been successfully used to treat chronic urinary tract infections. Since parenchymal involvement associated with renal insufficiency of varying degree is not infrequent in these patients, it was considered important to study the pharmacokinetics of TMP and SMP in a fixed dose combination. Four groups of patients were studied: 1) 4 patients with endogenous creatinine clearance (CLcR) between 80 and 40 ml/min; 2) 3 patients with CLcR between 40 and 10 ml/min; 3) 3 patients on chronic peritoneal dialysis (CAPD); and 4) 3 patients on haemodialysis. A single oral dose of 250 mg TMP and 200 mg SMP was given to each patient. Multiple samples were collected over 9 days and the following pharmacokinetic parameters were calculated: total area under the plasma level curve, slow disposition rate constant beta and the corresponding t1/2 beta, plasma clearance and the apparent volume of distribution. The results show that the two moieties of the TMP-SMP combination behaved differently in uraemic patients as fas as elimination rate was concerned. TMP was eliminated more slowly both in patients with diminished renal function and in those subjected to haemo- or peritoneal dialysis. The reduction in the rate of elimination of TMP was significantly correlated with the degree of renal impairment. The elimination of SMP, however, was not significantly affected by the reduced renal function; indeed a tendency to increase was noted, at least in dialyzed patients.(ABSTRACT TRUNCATED AT 250 WORDS)

Inhibition of glucagon secretion in the human newborn by glucose infusion

Plasma glucagon, serum insulin, and blood glucose responses during a 30-min glucose (1 g/kg body wt) or saline infusion were reported in 37 full-term and 35 preterm infants. They were studied either on the first day of life before feeding was initiated or during the first week of life. Glucose infusion promptly suppressed glucagon secretion in all infants even from the initial hours of extrauterine life. The mean maximal decrement in percentage in the full-term infants on the day of birth and older was 54 +/- 4% and 61 +/- 6%, respectively, while the maximal decrement in the preterm infants on day of birth and older was significantly lower (44 +/- 3% and 38 +/- 4%, respectively). The insulin response to glucose was variable in all infants and most of them showed a delayed rise of serum insulin. No change in plasma glucagon, blood glucose, and serum insulin was observed during and after saline infusion.

A quantitative immunofluorescent study of the endocrine cell populations in the developing human pancreas

The immunofluorescent cell content of the pancreas of 8--40-wk fetuses and of 1.5--5-mo Caucasian infants was quantitatively evaluated using anti-insulin, anti-glicentin, anti-glucagon, anti-somatostatin, and anti-pancreatic polypeptide antisera. The most significant findings are: (1) the pancreas of 8--10 wk fetuses contains a sizable population of endocrine cells reacting exclusively to anti-glicentin antiserum. This cell population decreases and disappears in later stages and is replaced by the adult type glucagon/glicentin immunoreactive cell; (2) the pancreatic polypeptide-rich region shows a lower relative endocrine cell content as compared with the glucagon-rich region and its islets appear smaller; (3) in the total pancreas, the relative (volume density) and absolute (microliter) insulin cell content increases regularly with age, while the relative volume of glucagon cells peaks in fetal life (wk 17--20) to decrease in infants, although remaining at higher levels than in adults; the relative and absolute volumes of somatostatin cells are elevated in fetal and infant stages studied where they represent the second most abundant cell type, while pancreatic polypeptide cells appear to least abundant cells during prenatal and infant life. These data show several differences with the pattern of the respective endocrine cell populations in the adult pancreas.

Role of thyrotrophin-releasing hormone in the development of pituitary-thyroid axis in four anencephalic infants

Anencephaly provides a unique model for studying endocrine functions in absence of hypothalamic influence. We previously reported that in anencephalic newborns both pituitary TSH-secreting cells and the thyroid were normal and were able to function if adequately stimulated. In order to verify if the normal development of the pituitary-thyroid axis in these infants depends on TRH of extrahypothalamic origin, we measured endogenous TRH levels in the clear fluid of a cyst of the cerebro-vasculosa in 4 anencephalic newborns. In these cysts were also injected 200 micrograms of synthetic TRH and evaluated TSH response in peripheral blood samples. Endogenous TRH was detectable in the cysts of the cerebro-vasculosa in 3 of the 4 infants. In all 4 cases serum TSH sharply increased after TRH administration. Our data suggest that the normal development of the pituitary-thyroid axis in anencephalic infants either requires no TRH or depends on extrahypothalamic TRH. In this latter case TRH produced by other areas of the central nervous system might be secreted into the cysts of the cerebro-vasculosa, actively transported to the hypophyseal vessels, and might thus reach the pituitary to stimulate TSH-cells growth and function.

Glicentin precedes glucagon in the developing human pancreas

A quantitative evaluation of immunofluorescence elicited by anti-insulin, anti-glucagon, anti-glicentin, anti-somatostatin and anti-pancreatic polypeptide antisera has been carried out in the pancreas of 5 human fetuses from 3.0 to 9.6 cm C.R. The data obtained indicate that while insulin and somatostatin-containing cells are approximately in similar proportions with respect to the other endocrine cell types in the five fetuses studied, the glucagon and glicentin immunoreactive cells and the pancreatic polypeptide cells are not : a) pancreatic polypeptide-containing cells increase in proportion as fetuses grow older; b) the youngest fetuses (3.0 to 4.3 cm C.R.) contain a high proportion of cells reacting to anti-glicentin antiserum only (GLI-cells) and a small proportion of cells stained both with the anti-glicentin and anti-glucagon antisera (GLI/GLU-cells). However, the latter cell type which stains similarly as the postnatal and adult pancreatic A-cell (GLI-cells are not detectable in the postnatal and adult pancreas) increases iin proportion in older fetuses, while the proportion of GLI-cells decrease. The data suggest that the definitive adult-type A-cell matures from a GLI-cell type which is not able to convert glucagon precursors GLI(s) into glucagon.

Atypical Reserve Cell Hyperplasia of Cervical Glands, Simulating Adenocarcinoma. An Undescribed Reversible Lesion in a Woman Taking Oral Contraceptives

On the basis of a characteristic lesion of the endocervical mucosa in a woman who had taken contraceptives for 4 years, the authors review the problem of these alterations, also in light of their personal experience.

Serum and saliva levels of a trimethoprim-sulfamethopyrazine combination in man

A combination of trimethoprim (TMP) and sulfamethopyrazine (SMP) was administered to six healthy volunteers for 8 days, according to the proposed therapeutic repeated dose schedule. The weak base TMP (pKa = 7.3) and the weak acid SMP (pKa = 6.1) were measured simultaneously in serum and saliva, both under normal conditions and after stimulation of saliva flow. The flow of saliva was stimulated by chewing plastic material in order to obtain saliva at a pH close to the normal plasma pH of 7.4. This procedure excluded pH-dependent distribution effects. Under these experimental conditions a highly significant correlation was observed between the serum and saliva concentrations of both drugs, with very small inter- and intraindividual variations. Substantial agreement was found between the saliva:serum concentration ratio and the fractions of both drugs not bound to plasma protein. Some discrepancies were noted, probably due to minor shifts in saliva pH during the collection period.

[2-Substituted thiazole derivatives with possible antitumor activity]

Some di-N-(20-aminothiazolyl)derivatives were synthesized and then cyclyzed to give the thiazolidin-4-ones (II) and (III). All compounds were tested for their activity against the leukemic P 388 tumor system in mice.

Human fetal insulin secretion in response to maternal glucose and leucine administration

Maternal and fetal serum insulin response to glucose, leucine and leucine plus glucose was examined by infusions to normal pregnant women at term immediately before cesarean section. The maternal infusion of glucose (50 g) for 30 or 60 minutes was associated with a marked hyperglycemia and with a rise in serum insulin in mother and fetus. The fetal insulin response to the administration of glucose for 60 minutes was higher (p less than 0.01) than when the same dose was given for 30 minutes, while the blood glucose was lower (p less than 0.01). The maternal infusion of a smaller dose of glucose (25 g) or leucine (15 g) for 60 minutes produced an increase in serum insulin only in the mothers. However the simultaneous administration of these substances stimulated maternal and fetal insulin secretion. The fetal insulin level produced was similar to that seen after the maternal infusion of 50 g of glucose for 60 minutes, while the cord blood glucose was slightly higher but significantly different (p less than 0.01) than that seen in the saline infused group.

Thyroid-pituitary function in eight anencephalic infants

The function of the thyroid pituitary axis was investigated in 8 anencephalic infants with no hypothalamus. Thyrotrophin (TSH), thyroxine (T4), 3,5,3'-triiodothyronine (T3) and 3,3',5'-triiodothyrone (reverse T3 and rT3) were measured in the cord blood in 5 cases and during the first 4 h of life in 3 cases. TSH response to synthetic thyrotrophin-releasing hormone (TRH) (200 microgram iv) was carried out in two cases and thyroid hormone response to bovine TSH (5 IU iv) was evaluated in 3 cases. The following results wre obtained: 1) The pituitary gland was found in all infants and the thyroid was normal both grossly and by microscopic sections. 2) TSH levels at birth were normal but there was no spontaneous post-delivery surge. 3) T4 and T3 values at delivery were within normal range, but no T3 increase was present after birth. rT3 levels at birth were higher than normal in 3 cases. 4) Administration of TRH caused a marked and rapid TSH release. 5) Thyroid hormone response to TSH was normal. The present findings suggest that in the anencephalic foetus both pituitary TSH-secreting cells and the thyroid gland do develop despite the absence of the hypothalamus and are able to function if adequately stimulated.

Krabbe's disease with unusual clinical and morphological features

A progressive encephalopathy appeared in two sibs aged 7 and 5 months. The children died at 23 respectively 29 months of age. Autopsy of the second child disclosed a severe demyelination involving the whole brain. Only few globoid cells were identified. Ultrastructural and biochemical investigations confirmed the diagnosis of Krabbe's disease.

[Correlation between antibacterial activity of some cephalosporins and pharmacokinetic properties "in vitro" (author's transl)]

A new apparatus is described which can be used to investigate the in vitro antibacterial activity of antibiotics as a function of different concentration-time curves. The apparatus can be adjusted to simulate the biexponential serum level curves observed in vivo after oral or intramuscular administration. Preliminary studies were carried out with cefazolin against an E. coli strain simulating initial concentrations of 5, 10 and 20 micrograms/ml that decreased exponentially with half-lives of 30, 60 and 120 min. In all the situations tested there was an initial phase of rapid bactericidal activity followed by a phase of bacteriostatic activity, whose length depended on the drug elimination rate but was relactively independent of the initial concentrations. Bacterial regrowth occurred when the antibiotic concentration fell below the minimum inhibitory concentration (MIC) of the drug. The antibacterial activity of cefazolin, cephacetrile, and cephradine against an E. coli strains was also investigated, in a medium containing 4% human albumin, simulating the serum level curves observed in humans after an intramuscular dose of 1 g. The results obtained confirm that, for cephalosporins, the dosage schedule should be adjusted taking into account the potency of the drug (MIC) and its rate of elimination.

New in vitro model to study the effect of antibiotic concentration and rate of elimination on antibacterial activity

A new apparatus is described which serves to investigate the in vitro antibacterial activity of antibiotics as a function of different concentration time curves. The apparatus can be adjusted to simulate the biexponential serum level curves observed in vivo after oral or intramuscular administration. Preliminary studies were carried out with a cephalosporin derivative, cefazolin, against Escherichia coli and Klebsiella sp. strains simulating initial concentrations of 5, 10, and 20 mug/ml that decreased exponentially with half-lives of 30, 60, and 120 min. Surviving cells were counted at 1-h intervals for 10 h. In all the situations tested there was an initial phase of rapid bactericidal activity followed by a phase of bacteriostatic activity, whose length depended on the drug elimination rate but was relatively independent of the initial concentrations. Bacterial regrowth occurred when the antibiotic concentration fell below the minimum inhibitory concentration of the drug against the strains tested. The antibacterial activity of cefazolin, cephacetrile, and cephradine against E. coli and Klebsiella strains was also investigated, in a medium containing 4% human albumin, simulating the serum level curves observed in humans after an intramuscular dose of 1 g. The results obtained suggest that, for cephalosporins, a longer half-life might be more useful than higher peak levels.

Effect of priming of amino acids on insulin and growth hormone response in the premature infant

Glucose, alpha-amino nitrogen, serum insulin, and HGH were studied in preterm infants during the first 24 hours of life. Glucose infusion (1.25 gm.) resulted in a slight elevation of serum insulin. When this amount of glucose was infused during the last 30 minutes of a two-and-a-half-hour infusion of a mixture of essential amino acids, there was a rapid and striking increase in serum insulin. However, this increase was not associated with a faster glucose disposal rate. The administration of this mixture of amino acids doubled the basal level of alpha-amino nitrogen, and during the first two hours, before glucose infusion, it caused a significant rise of serum insulin and HGH. In both cases glucose caused an increase of HGH secretion that was not significantly different in the two groups of infants.

Human maternal and fetal serum insulin and growth hormone (HGH) response to glucose and leucine

Maternal and fetal serum insulin and HGH responses to glucose, leucine, and glucose plus leucine were examined by infusions to pregnant women at term immediately before cesarean section. Leucine (15 gm.) with glucose (50 gm.) administered for 30 minutes to the mothers stimulates markedly maternal and fetal insulin secretion while infusion of glucose (50 gm.) causes a lower insulin response. When infusing glucose alone we noted that the duration rather than the degree of hyperglycemia determined the fetal insulin response. In fact, when glucose is given to the mother for 60 minutes the fetal insulin response is higher than when the same dose is infused for 30 minutes. Maternal infusion of leucine (15 gm.) for 30 minutes elicits only a very slight increase of insulin secretion in the mother and no change in the fetus. None of the infusions causes any alteration whatsoever in either maternal or fetal HGH secretion.

Endometrial Carcinoma under the Age of 40

Endometrial adenocarcinoma in women under the age of forty presents a different course according to its histology. Adenocarcinomas of the endometrium may be classified into 4 main types: type 1, homologous or endometrioid; type 2, fallopian-like; type 3, cervical-like; type 4, unclassifiable. The majority of homologous adenocarcinomas have a relatively benign course, whereas the other types are definitely malignant. There is no room for doubt between adenocarcinoma and atypical endometrial hyperplasia in women under forty unless the histological pattern is of the homologous or endometrioid type, because the other patterns are definitely malignant.

Effect of glucose priming on insulin response in the premature infant

Our paper deals with premature infants in the first twenty-four hours of life and reports the effect of a preinfusion of glucose on glucose administration. Glucose infusion (2.5 gm.) resulted in a slight elevation of serum insulin. When this administration of glucose was preceded by a two-hour infusion of glucose, there was a striking increase in serum insulin.

Morphological Typing of Endometrial Adenocarcinoma as the Basis of the Natural History of the Tumor

Current ideas on Müllerian tumors of the ovary are applied to the classification of endometrial adenocarcinomas, which are divided into four main histotypes: Type 1 or homologous or endometrioid (65 % of cases); Type 2 or Fallopianlike (15.8 %); Type 3 or cervical-like (13.4%) and Type 4 or unclassifiable (5%). This classification aims to provide a useful morphological criterion for forecasting the sensitivity of endometrial adenocarcinomas to endocrine treatment with progestational agents. Type 1 accounts for about 80 % of all adenocarcinomas of the endometrium in the fifth decade of life, which is supposed to be the period most exposed to estrogenic stimulation. These adenocarcinomas represent only 14 % of all endometrial adenocarcinomas. The above results are based on a 155-case series.

Insulin secretion in the premature infant. Response to glucose and amino acids

Serum insulin was measured in fifty-one premature infants in the first twenty-four hours of life following the administration of glucose, a mixture of amino acids, or glucose with an amino acid mixture. Infusion of glucose (1.25 gm.) caused a rapid increase of blood glucose and a small rise in serum insulin. The amino acid mixture (2.5 gm.) produced, on the contrary, a rapid and marked increase of serum insulin but only a slight rise of blood glucose. When the dose of the amino acid mixture was halved, rise of serum insulin and blood glucose was small. Combining the reduced dose of amino acid mixture with glucose produced a rapid and striking increase of both serum insulin and blood glucose.

Effect of theophylline, glucagon and theophylline plus glucagon on insulin secretion in the premature infant

Serum insulin was measured in thirty premature infants in the first twenty-four hours of life following the administration of theophylline, glucagon, or theophylline plus glucagon. Theophylline (1 mg. per min.) produced a striking rise in serum insulin without change in blood glucose. Neither glucagon (0.4 γ per min.) nor theophylline (0.5 mg. per min.) produced any significant change in the levels of blood glucose and serum insulin. However, the simultaneous administration of these doses of glucagon and theophylline was followed by a progressive rise in blood glucose and serum insulin. The insulin secretion with this combination exceeded that seen with a rapid injection of 300 γ of glucagon.