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G Molnar-Nadasdy

Publications and source records attributed to G Molnar-Nadasdy.

5 recordsLinked to original sources
PubMed1999

Chronic effect of pneumoperitoneum on renal histology.

BACKGROUND AND OBJECTIVE: Transient intraoperative oliguria is a constant phenomenon during laparoscopic procedures. Laboratory studies have demonstrated that this effect is secondary to a decrease in renal blood flow caused by the pneumoperitoneum. With the advent of laparoscopic harvest of the kidney for renal transplantation, a concern is that increased intra-abdominal pressure may compound the effect of acute cold and warm renal ischemia during transplantation. Acute transient renal ischemia can produce chronic sclerosing histopathologic changes in native kidneys which are similar to those seen in chronic allograft rejection. The effect of positive-pressure abdominal pneumoperitoneum (15 mm Hg) on native kidneys was examined using a rodent model. The effects on renal function and histologic features were also studied. MATERIALS AND METHODS: Twenty-four Harlan Wistar-Furth rats were divided into four groups: controls, 1-hour pneumoperitoneum-91-day survival, 5-hour pneumoperitoneum-91-day survival, and 5-hour pneumoperitoneum-7-day survival. Control animals underwent placement of the Veress needle and anesthesia but no induction of pneumoperitoneum. At the time of sacrifice, blood was sampled for serum creatinine measurement. Both kidneys were harvested for frozen and permanent section and stained using hematoxylin and eosin. Specimens were graded for inflammatory and ischemic/sclerotic changes in the interstitium, tubules, glomeruli, and vasculature by a renal pathologist using a histologic score (0-3). RESULTS: In all groups, at a sacrifice interval of either 1 week or 3 months, there were no statistical differences in the histologic score, serum creatinine concentration, or renal weight. CONCLUSIONS: In a rodent model, no signs of chronic ischemic histologic changes were detected for a period of 3 months after up to 5 hours of pneumoperitoneum. As well, there was no change in the serum creatinine concentration.

Animals↗
PubMed1994

Placental cryptococcosis in a mother with systemic lupus erythematosus.

There are many pregnant mothers who have acquired immunodeficiency syndrome or who require immunosuppressive therapy for sundry reasons. Despite this, we have been able to find only one English-language report of placental cryptococcosis. We have had an opportunity to treat a pregnant mother who suffered from cryptococcal meningitis that complicated steroid treatment for lupus erythematosus. At 31 weeks' gestation, fetal distress necessitated delivery by cesarean section. The placenta had focally abundant intervillous and perivillous cryptococcal yeast cells, but there was no chorioamnionitis or villitis. Although there were no clinical or placental signs of transplacental infection, immunohistochemical labeling of villous stromal cells showed a conspicuously increased number of fetal macrophages.

Adult↗
PubMed1992

Meconium-induced umbilical cord vascular necrosis and ulceration: a potential link between the placenta and poor pregnancy outcome.

The literature lacks epidemiologic study of pregnancy outcome with light-microscopic meconium-related lesions. We recently described previously unreported meconium-induced necrosis of placental and umbilical cord vessels and hypothesized that the lesions represent preceding vasocontraction and fetal hypoperfusion. Preliminary experiments then confirmed that meconium produces vasocontraction in isolated umbilical venous tissue. In the present study, we examined whether clinically meaningful abnormalities occur with these vascular signs of remote fetal meconium discharge. In a light-microscopic review of 1100 meconium-stained placentas, we found ten with meconium-induced vascular necrosis. In six of these ten cases, fetal distress necessitated cesarean delivery. Seven newborns had Apgar scores of 3 or less at 1 minute, and each of the seven cases tested had umbilical arterial pH less than 7.19. Because seven of the ten infants were born after December 1, 1989, clinical follow-up was limited. One died, another has neurodevelopmental deficiency, and a third has experienced enlargement of head circumference from the 50th percentile at birth to the 95th percentile at 10 months of age. Two placentas had umbilical cord ulceration, a lesion that has rarely been reported in the literature. We conclude that meconium-induced vascular necrosis seems to be a meaningful, detrimental lesion.

Amniotic Fluid↗
PubMedDate not supplied

Cell proliferation in the developing human kidney.

In a previous study, utilizing antibodies to proliferating cell nuclear antigen (PCNA), we determined the proliferation index (PI) (percentage of PCNA-positive cells) of intrinsic renal cell populations in the normal adult and pediatric kidney. We have found that the PI in both adult and pediatric kidneys was very low (below 0.5 in all examined cell populations). In our present study, we investigated cell proliferation in the developing human kidney with an antibody to PCNA. Histologically normal kidneys were collected from 25 fetuses (spontaneous abortions and stillborns) ranging from 10 wk of gestation to term. Immature mesenchyme (blastema), immature early tubules, ampulla of ureteric bud, proximal tubules, Tamm-Horsfall protein (THP)-positive tubules, distal tubules, collecting ducts, and glomeruli were evaluated separately. The PI for each cell population was calculated. The PI of immature early tubules remains high (33-43) throughout embryonic life. The PI of blastemal cells is initially similarly high, but gradually decreases starting from the second trimester. The PI of THP-positive tubules, distal tubules, collecting ducts, and glomeruli starts out relatively high (5.9, 8.6, 6.0, and 12.4, respectively) and decreases gradually as term approaches (1.8, 1.3, 1.2, and 1.4, respectively). Interestingly, as soon as proximal tubules become differentiated (appearance of light microscopic features of proximal tubular epithelium with TP lectin positive brush border), their PI becomes very low (below 1) irrespective of the age of the kidney. This is the first quantitative study to show changes of the PI in various renal cell populations during human nephrogenesis. These changes in the PI relate to the stage of differentiation of the developing nephron segments.

Cell Division↗