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Biomedical subjects

P Kramer

Publications and source records attributed to P Kramer.

At least 91 records · Page 5Linked to original sources
PubMed1991

Retroperitoneal fibrosis: report of 12 cases and a review of the literature.

Twelve patients with retroperitoneal fibrosis (RPF) over a 10-yr period (1980-1990) are reviewed. The clinical manifestations, radiographic findings as well as treatment and follow-up are discussed and a review of the literature is presented. Nowadays the diagnosis can be established with near-certainty by means of computed tomographic scan (CT). In case of diagnostic problems, CT- or ultrasound guided percutaneous needle biopsy can aid the diagnosis. There is now considerable evidence that RPF can be treated effectively with corticosteroids and should be considered the treatment of choice, surgery being confined to medical failures or those who do not tolerate steroids. Early and frequent CT follow-up may demonstrate the beneficial response to steroids, thereby obviating the need for exploratory or therapeutic surgery. In steroid-resistant cases, when there is no doubt about the initial diagnosis, azathioprine or cyclophosphamide may be used. Long-term follow-up is recommended in all patients.

Adrenal Cortex Hormones↗
PubMed1991

Percutaneous balloon mitral valvuloplasty in a pregnant woman with mitral stenosis, sickle cell crisis and acute pulmonary edema. A case report.

A woman with acute congestive heart failure secondary to mitral stenosis and sickle cell crisis was treated successfully with a combination of an exchange transfusion and percutaneous balloon valvuloplasty. That combination provided an alternative to surgical mitral commissurotomy, with its significant risks for both the mother and fetus. The patient was able to undergo an uncomplicated pregnancy course despite the increased risk of cardiac decompensation in the intrapartum and postpartum period.

Adult↗
PubMed1990

Cyclic changes in conjunctival smears from menstruating females.

Cytohormonal evaluation has become an accurate procedure for the assessment of estrogenic effect on the vaginal and buccal mucosa. Both show a cyclical variation in the maturation index (an "estrogenic value" based on epithelial maturation). Conjunctival smears were taken from the temporal conjunctiva of 11 premenopausal and 7 postmenopausal females on a near-daily basis. No females had evidence of ocular surface disease, including keratoconjunctivitis sicca. After fixation and Papanicolaou staining, maturation indices for each specimen based on the differential morphology were red in a single blind fashion by a Papanicolaou cytologist. Cyclical variations paralleling the menstrual cycle in eight of nine premenopausal women were noted with maturation index values ranging from 30 (low estrogen effect) to 82 (high estrogen effect), peaking on day 11 or 21 of the menstrual cycle. No cyclical change was found in postmenopausal smears and smears of subjects with endocrine abnormalities. Maturation index values ranged from 30 to 38. Conjunctiva appears to be an estrogen-sensitive epithelium.

Cell Division↗
PubMed1990

Effects of a luteinizing hormone-releasing hormone antagonist in late-juvenile female rats: blockade of follicle growth and delay of first ovulation following suppression of gonadotropin concentrations.

Subcutaneous injections of an antagonist against luteinizing hormone-releasing hormone (LHRH-A, Org, 30276) were administered to late-juvenile female rats. The effects on timing of vaginal opening and first ovulation on serum gonadotropin concentrations and on follicle growth were studied. The dose of 100 micrograms LHRH-A/100 g body wt, given on Days 28, 31, and 34, did not influence timing of first ovulation. After administration of 500 micrograms LHRH-A/100 g body wt, ovulation was retarded by 4.7 days if injections were given on Days 28 and 31; by 6.7 days if given on Days 28, 31, and 34; and by 11.5 days if given on Days 28, 31, 34, and 37. Serum LH and FSH concentrations 3 days after the first, second, and third injections of 500 micrograms LHRH-A were significantly (p less than 0.01) lower than in saline-treated controls. Ovarian follicle counts showed decreased numbers of (antral) Class 2, 3, and 4 follicles 3 days after injection of 500 micrograms LHRH-A/100 g body wt on Day 28; a significantly higher number of Class 1 follicles and a further decrease in Class 2, 3, and 4 follicles 3 days after the second LHRH-A injection; and total absence of Class 3, 4, and 5 follicles 3 days after the third LHRH-A injection. Six days after the third LHRH-A injection, Class 3 and 4 follicles reappeared in the ovaries.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1990

Hepatitis B vaccination of haemodialysis patients: randomized controlled trial comparing plasma-derived vaccine with and without pre-S2 antigen.

The pre-S2 protein of the hepatitis B virus envelope evokes anti-pre-S2 antibodies and enhances the anti-HBs response after vaccination in mice. In order to evaluate the immunogenicity of the pre-S2 Ag in man, 102 HBsAg, anti-HBs, anti-HBc-negative haemodialysis patients were vaccinated at random according to one of four vaccination schedules: 5 micrograms plasma vaccine Pasteur (containing 1% pre-S2) or 20 micrograms plasma vaccine MSD (no pre-S2) at 0, 1, 2, 4, 6 and 12 months; or 10 micrograms Pasteur or 40 micrograms MSD at 0, 1, 2 and 6 months. Anti-HBs levels were measured by RIA and expressed in IU l-1; anti-pre-S2 response was evaluated by both EIA and Western blot analysis. Eighty-four per cent (95% confidence interval: 75-93) of the patients exhibited an anti-HBs response of 2 IU l-1 or more and 71% (95% confidence interval: 61-81) reached an anti-HBs level of at least 10 IU l-1 within 13 months of the start of vaccination. Anti-HBs response correlated with age (the response rate decreased with increasing age) but not with either the type of vaccine or dosage. An anti-pre-S2 response was observed in 16% (EIA) and 46% (Western blot) of the patients immunized with the Pasteur vaccine and none (EIA, Western blot) of the MSD group. The level of anti-pre-S2 antibodies correlated with high anti-HBs titres; an anti-pre-S2 response occurred in only one anti-HBs-negative patient.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1990

Effect of immunomodulator thymopentin on impaired seroresponse to influenza vaccine in patients on haemodialysis.

In a double-blind placebo-controlled multicentre study, the effect of the immunomodulator thymopentin (TP5) on the antibody production to trivalent influenza vaccine was tested in 108 patients on chronic intermittent haemodialysis (HD). Antibody production was determined in pre- and postvaccination sera. Compared to a group of 35 young healthy adult control subjects, HD patients showed a clearly impaired seroresponsiveness to all three vaccine components, regardless of treatment with TP5 or placebo. We conclude that TP5 administration is not able to enhance humoral immunity in patients on chronic intermittent HD.

Adolescent↗
PubMed1990

Short- and long-term effects of an LHRH antagonist given during the prepubertal period on follicle dynamics in the rat.

The effects of the suppression of the high gonadotrophin concentrations normally present by the end of the second week of life on ovarian follicle dynamics were studied in immature rats. Gonadotrophins were suppressed by treatment with an LHRH antagonist (LHRH-A; Org. 30276) on days 6, 9, 12 and 15, and the total population of ovarian follicles was studied at 15 and 28 days, on the day of first oestrus and on the day of oestrus at or following 90 and 300 days of age. Primordial follicles were counted and growing follicles were counted and measured. In rats treated with LHRH-A, follicle recruitment into the growing pool was clearly diminished; the number of growing follicles was significantly (P less than 0.01) lower up to the day of first oestrus and the pool of primordial follicles was significantly (P less than 0.05) larger at 15 and 28 days. Ovarian weights were significantly lower in rats treated with LHRH-A until at least 90 days of age. However, on the day of oestrus at or after 90 and 300 days of age, there were no differences in either the pool of primordial follicles or the pool of growing follicles between rats treated with LHRH-A and control rats. There was also no difference between groups in the number of fresh corpora lutea at these ages. It was concluded that the early peak in gonadotrophin concentrations in immature rats causes substantial recruitment of follicles into the growing pool.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1989

Ovarian follicle dynamics in immature rats treated with a luteinizing hormone-releasing hormone antagonist (Org. 30276).

The high concentrations of gonadotropins present in immature female rats by the end of the second week of life were suppressed by treatment with an antagonist against luteinizing hormone-releasing hormone (LHRH-A; Org. 30276) on Days 6, 9, 12, and 15 of life. Differential ovarian follicle counts were made on Days 15, 22, 28, and on the day of first estrus of all growing follicles and follicles greater than or equal to 100 x 10(5) microns 3 (mostly antral). In LHRH-A-treated rats, a retardation of follicle growth was noted on Day 15, followed by a gradual loss of growing follicles that amounted to 20% on Day 22 and 40% on Day 28; at first estrus, the total population of growing follicles was only 50% of that present in control rats. Antral follicles, first present at 22 days of age, were lower in number at 28 days of age and at first estrus in LHRH-A-treated rats; this was true for both healthy and atretic follicles. Ovarian weights were significantly reduced in LHRH-A-treated rats at 15 and 28 days of age and on the day of first estrus. However, the numbers of corpora lutea following the first, and normally timed, ovulation were the same in both groups. It was concluded that for early recruitment of follicles to reach a full-sized pool of growing follicles at the age of puberty, high concentrations of gonadotropins early in life have a significant role.

Animals↗
PubMed1989

Advancement of first ovulation by the opioid antagonist naltrexone.

The opioid antagonist naltrexone was administered to female rats during the late juvenile period, and its effects on sexual maturation were studied. Naltrexone treatment (2.5 or 20 mg/kg; four daily injections at 2-h intervals) at 28-32 days of age advanced first ovulation in about 55% of the rats. When naltrexone (20 mg/kg) was administered at 30-34 days of age, 75% of the rats responded. In these rats, first ovulation was advanced by 3.4 days and their body weight was 15.1 g lower than in control rats at first ovulation (p less than 0.01). Similar naltrexone treatment at younger (starting on Day 24 or 26) or older (starting on Day 32 or 34) ages did not advance first ovulation. The numbers of ova released in advanced, nonadvanced, and control rats were similar. A significant increase in serum luteinizing hormone (LH) concentration was seen 15 min after naltrexone injection (20 mg/kg) at all ages studied; the increase was significantly higher (p less than 0.05) at 30 days of age than before or after that age. Relatively high response to naltrexone (2.5 mg/kg) was seen from 8 to 4 days before first ovulation. Taken together, these data suggest that during the late juvenile stage (8 - 4 days before first ovulation) endogenous peptides critically restrict LH secretion and may constitute a hypothalamic restraint on the onset of puberty. However, changes in pituitary responsiveness to luteinizing hormone-releasing hormone may be part of the mechanism behind the high LH response to naltrexone in rats during the late juvenile stage.

Animals↗
PubMed1989

Contrasting response to cyclosporin in refractory nephrotic syndrome.

We studied the effects of cyclosporin A (CsA), given for three months, in 14 patients with nephrotic syndrome refractory to treatment with prednisone and/or other immunosuppressants. CsA was given in a starting dose of 6 mg/kg and plasma through levels (RIA) were kept between 50 and 150 ng/ml. Diagnosis included: idiopathic membranous glomerulonephritis (n = 6), focal segmental glomerulosclerosis (n = 3), minimal change disease (n = 3) and membranoproliferative glomerulonephritis (n = 2). Three patients with non-immunologically mediated nephrotic syndrome due to Alport's syndrome were studied as well. Considering all patients and diagnostic groups together, proteinuria decreased from 9.0 +/- 4.3 to 4.7 +/- 3.8 g/24 h during CsA treatment (mean +/- SD; p less than 0.01). However, serum creatinine increased from 121.8 +/- 60.5 to 150.4 +/- 64.6 mol/l (p less than 0.01) and glomerular filtration rate as estimated by 24-hour creatinine clearance fell from 85.5 +/- 33.7 to 72.1 +/- 37.2 ml/min (p less than 0.05). When compared to other diagnostic groups, fractional excretion of protein, i.e. protein excretion corrected for changes in glomerular filtration rate, fell only in IMGN (ANOVA, p less than 0.05). We conclude that CsA reduced proteinuria in patients with refractory nephrotic syndrome. In the majority of these patients this reduction could be due to a renal hemodynamic, rather than an immunomodulatory effect of the drug. Only in IMGN the latter action of the drug may be of importance.

Adult↗
PubMed1988

Dysphagia--etiologic differentiation and therapy.

The case described in this paper demonstrates the importance of the history of dysphagia in diagnosing the cause of a swallowing disorder. The history localized the cause of the patient's dysphagia to the lower esophagus. It further established that the lesion was benign, that the dysphagia occurred only when solids were swallowed, and that even then it occurred intermittently--the sine qua non of a lower esophageal ring. For patients with a swallowing disorder, the preferred initial diagnostic procedure is a barium swallow. The procedure is noninvasive, it is the least costly option, and it detects lower esophageal rings, motility disorders, external compressions of the esophagus, and most mucosal and intraluminal diseases. Endoscopy (with or without biopsy) is the procedure of choice in evaluating mucosal and intraluminal disease, in that it offers a direct view of the lesion, as well as tissue for histopathologic examination. If the cause of a patient's dysphagia is not clear, other procedures may be chosen; they include giving the patient a bolus of food with barium. Patients with a lower esophageal ring should be urged to chew their food carefully. If the dysphagia is not satisfactorily controlled, esophageal dilation should be considered.

Deglutition↗
PubMed1988

The preparation and characterization of Cr(III) and Co(III) complexes of GDP and GTP and their interactions with avian phosphoenolpyruvate carboxykinase.

The exchange inert coordination complexes, Cr(H2O)4GDP, Cr(H2O)4GTP, Cr(NH3)4GDP, Cr(NH3)4GTP, Co(NH3)4GDP, and Co(NH3)4GTP have been synthesized and characterized. The lambda and delta coordination isomers of Cr(H2O)4GDP, Cr(NH3)4GDP, and the four Cr(H2O)4GTP isomers have been separated by reverse phase HPLC and characterized by their CD spectra. While the isomers of Co(NH3)4GTP have not been successfully separated, 31P NMR spectroscopy reveals the presence of the lambda and delta forms. The complexes, Cr(H2O)4GDP, Co(NH3)4GDP, Cr(H2O)4GTP, and Co(NH3)4GTP, are linear competitive inhibitors of avian phosphoenolpyruvate carboxykinase. The Ki values of 30 microM, 540 microM, 40 microM, and 12 microM, respectively, were determined for these complexes using Mn-IDP as the nucleotide substrate in the phosphoenolpyruvate carboxylation direction or Mn-ITP as nucleotide substrate for the oxalacetate decarboxylation reaction. The lambda and delta isomers of Cr(H2O)4 GDP show little specificity (a twofold maximum difference in Ki) for the enzyme. The isomeric forms of Cr(H2O)4 GTP demonstrate no observed stereoselectivity of interaction with the enzyme. All of the complexes tested, except for Cr(NH3)4GDP and Co(NH3)4GDP, which have larger Ki values, are good substrate analogs for P-enolpyruvate carboxykinase. When the substrate is Mn-GTP, fixed at 0.2 mM at pH 6.0, enzyme activity is stimulated two- to two and a half-fold by Cr(H2O)4GTP. A Dixon plot reveals that the stimulatory effect is saturated at 0.4 mM Cr(H2O)4GTP. The interaction of the enzyme with Cr(H2O)4GTP appears to produce a "memory" effect which is manifest with guanosine nucleotide substrates, but which is not observed with the alternative substrate Mn-ITP.

Animals↗
PubMed1988

Intact humoral immune response in patients on continuous ambulatory peritoneal dialysis.

After influenza vaccination no statistically significant difference in antibody response was observed between patients on continuous ambulatory peritoneal dialysis (CAPD) and healthy volunteers while a large group of hemodialysis (HD) patients was found to have a significantly lower response rate. This difference remained statistically significant when CAPD patients were compared to a matched HD group. As the antibody formation after influenza vaccination is a T cell-dependent phenomenon, the normal immune response to vaccination suggests an intact humoral and cellular immunity in CAPD patients.

Adolescent↗