Cytotoxic chemotherapy in the treatment of advanced renal cell carcinoma in the era of targeted therapy

BACKGROUND

Renal cell carcinoma (RCC) is a heterogeneous disease with regards to histology, progression, and response to treatment. Cytotoxic chemotherapy has been extensively studied in metastatic RCC (mRCC). Responses in most studies are modest and the mechanisms of resistance remain poorly understood. Targeted therapies have significantly improved outcomes in mRCC; however, most patients eventually relapse and die of their disease. Early clinical data suggest that combinations of chemotherapy and targeted agents are clinically active and are well tolerated.

METHODS

We reviewed the available literature for published clinical trials incorporating traditional chemotherapeutic agents in the treatment of mRCC. These papers were identified through a Medline search and were included if they employed at least one chemotherapeutic agent in the treatment of mRCC. The literature was also reviewed for information regarding mechanisms of chemotherapy resistance.

RESULTS

The data regarding the use of cytotoxic chemotherapy in mRCC consist of small, non-randomized phase I and II studies. The major response proportions with single agent chemotherapies are low but combination regimens either with other cytotoxic agents, cytokines, or targeted agents have demonstrated moderate activity. Disparate trial designs and lack of head to head clinical trials make it difficult to compare the efficacy of chemotherapy with that of immunotherapy or targeted agents. Chemotherapy is particularly useful in patients with collecting duct histology and predominantly sarcomatoid differentiation. Chemotherapy resistance may be mediated by overexpression of p-glycoprotein efflux pumps and the dysregulation of the microtubule-hypoxia inducible factor signaling axis.

CONCLUSIONS

The role of cytotoxic chemotherapy in the treatment for clear cell RCC remains poorly defined. Cytotoxic chemotherapy is considered a standard of care in patients with mRCC with predominantly sarcomatoid differentiation and collecting duct RCC variants (Motzer et al., 2014). Early trials combining chemotherapy with targeted therapies are generally well tolerated and show clinical activity. A better understanding of the biology of aggressive subsets of RCC and mechanisms of resistance will help elucidate the role of cytotoxic agents in the current treatment paradigm of RCC.

New insights into salivary lactate dehydrogenase of human subjects

Lactate dehydrogenase (LDH) is a ubiquitous enzyme that plays a significant role in the clinical diagnosis of pathologic processes. The purpose of the current study was to examine LDH activity and isoenzyme profile of whole saliva and to compare it with the LDH activity of salivary glands and plasma before and after exposure to cigarette smoke (CS). The range of LDH activity in whole saliva at rest was 360 to 430 U/L. The mean +/- SEM of LDH activity in parotid and submandibular/sublingual salivary secretions was 41.3 +/- 19.2 U/L and 77.5 +/- 30.4 U/L, respectively, which implied that 75% of the whole-saliva LDH originated from an extra-salivary gland source. The profile of salivary LDH isoenzymes was found to have an entirely different pattern from that found in plasma, similar to that found in oral epithelium, indicating that the major source of salivary LDH is probably the oral epithelium-shedding cells. Therefore, salivary LDH may be evaluated for possible oral mucosal pathologies in a manner similar to that used for evaluating other tissue pathologies--such as those in heart, muscle, or liver--that can be detected in plasma. Exposure of whole saliva to CS in vitro resulted in a 41% reduction in LDH activity. However, CS exposure had no effect on LDH activity in plasma. Whole saliva, in contrast to plasma, contains redox-active metal ions such as iron and copper that may enhance LDH loss of activity. Therefore we conclude that whole saliva in the presence of CS becomes a potent protein-modifying agent that can destroy some of its endogenous components.

Effect of cigarette smoke on salivary proteins and enzyme activities

Exposure of human plasma in vitro to gas-phase cigarette smoke (CS) causes a marked modification of plasma proteins as measured by protein carbonyl assay. Aldehydes present in CS may cause this elevation of protein carbonyls by reacting with sulfhydryl groups of proteins. Saliva is the first body fluid to confront the inhaled CS. Thus, in vitro exposure of saliva to nine "puffs" of CS also showed a distinct increase in protein carbonyls. Ascorbate and desferrioxamine mesylate had little effect on protein carbonyl formation, while GSH and N-acetylcysteine considerably inhibited the accumulation of protein carbonyls due to CS exposure. Following the exposure to CS, the activities of several salivary enzymes-amylase, lactic dehydrogenase (LDH), and acid phosphatase-were found to be significantly reduced (34, 57, and 77%, respectively). However, CS had no effect on the activities of aspartate aminotransferase and alkaline phosphatase. Addition of 1 mM of GSH and N-acetylcysteine considerably protected LDH and amylase activities, suggesting that sulfhydryl groups are affected in LDH and amylase. On the other hand, addition of 1 mM ascorbate caused a further loss of LDH and amylase activities, which could be partially prevented by the addition of desferrioxamine mesylate, implicating metal-catalyzed oxidation processes. Finally, loss of acid phosphatase activity was completely unaffected by any of the above antioxidants. It is concluded that the loss of salivary enzyme activities may be due to various agents in the CS that affect the enzyme activities via different mechanisms.

Tissue-specific p53 expression in the nervous system

P53 is a transcription factor that has been found to be expressed in association with cell proliferation and apoptosis. Previously, bacterial chloramphenicol acetyl transferase (CAT) enzymatic expression was predominantly found in the testes of p53 promoter driven-CAT transgenic mice. In the current study, we extended this study to survey p53 expression across both the central and peripheral nervous systems of the same strain of transgenic mice as well as their parental strain. High levels of p53 promoter driven-CAT activity was observed in the cerebellum, hippocampus, hypothalamus, pons, thalamus and upper cerebral spine. Furthermore, we consistently found unexpectedly high levels of p53 promoter-driven CAT expression in the eyes. These observations were reinforced by p53 protein analysis using a p53 pan ELISA assay. Immunohistochemical studies confirmed and further defined p53 expression in several regions of the nervous system. Significantly, p53 promoter-driven CAT expression was visualized in the Ammon horn of the hippocampus, in the Purkinje cells of the cerebellum and in the cornea as well as in the retina of the eye. Furthermore, strong p53 protein expression was found in the cornea of the parental mouse strain. p53 ELISA demonstrated a profile of p53 protein concentration, which correlate well with the high p53 promoter-driven CAT activities observed in the cerebellum, hindbrain, hypothalamus, thalamus, hippocampus, whole eyes as well as with the low CAT activities observed in the cortex and spinal cord. In both of these assays considerable p53 promoter activity and p53 protein levels were found in post-mitotic non-dividing cells.

Tissue-specific expression of the p53 tumor-suppressor gene in the intestine of transgenic mice exposed to DMH and p53 antibodies

We studied the tissue-specific expression of the p53 gene in different parts of the intestine of mice treated with low doses of a carcinogen and exposed to different p53 antibodies. The human p53 promoter-CAT transgenic mice were immunized with different p53 antibodies (monoclonal - PAb 421 and DO1, and polyclonal - H-p53 and anti-soluble p53 IgG) and then exposed to low doses of dimethylhydrazine (DMH). Enzymatic CAT activity was determined in the ileum and colon 8 weeks later after the final injection of DMH. Expression of the p53 transgene in the normal ileum was twice as high as in the colon. Treatment with DMH significantly decreased the expression of the p53 transgene both in the ileum (from 18% to 100%) and in the colon (from 10% to 52%). Vaccination of mice protected at least in part such a decrease. The most effective results were found after exposure of mice to polyclonal H-p53 and to a lesser extent to anti-p53 IgG. No difference was found in the effects of antibodies on the small and large intestines. We concluded that polyclonal antibodies were more effective than monoclonal ones in protection against anti-p53 action of DMH. The observation of these effects may make it possible to explain the higher antitumor activity of polyclonal antibodies.

Omega 3 fatty acids in bipolar disorder: a preliminary double-blind, placebo-controlled trial

BACKGROUND

Omega3 fatty acids may inhibit neuronal signal transduction pathways in a manner similar to that of lithium carbonate and valproate, 2 effective treatments for bipolar disorder. The present study was performed to examine whether omega3 fatty acids also exhibit mood-stabilizing properties in bipolar disorder.

METHODS

A 4-month, double-blind, placebo-controlled study, comparing omega3 fatty acids (9.6 g/d) vs placebo (olive oil), in addition to usual treatment, in 30 patients with bipolar disorder.

RESULTS

A Kaplan-Meier survival analysis of the cohort found that the omega3 fatty acid patient group had a significantly longer period of remission than the placebo group (P = .002; Mantel-Cox). In addition, for nearly every other outcome measure, the omega3 fatty acid group performed better than the placebo group.

CONCLUSION

Omega3 fatty acids were well tolerated and improved the short-term course of illness in this preliminary study of patients with bipolar disorder.

Interleukin-6 levels are not increased in women with postpartum thyroid dysfunction

Postpartum thyroid dysfunction (PPTD) is an autoimmune-mediated thyroid destructive process. Human interleukin-6 (IL-6) is a cytokine found to be increased in subacute thyroiditis, amiodarone-induced thyrotoxicosis, Graves' disease, and other thyroid destructive processes. We report serum IL-6 levels in PPTD in two independent studies. New York Study: In a previous prospective study we demonstrated that PPTD occurred in 25% (7/28) of women with type 1 diabetes mellitus. IL-6 determinations were made on the frozen serum samples of these 28 women during each trimester of their pregnancy and at 1.5, 3, 6, 9, and 12 months postpartum. IL-6 levels were found to be similar in women with PPTD compared with women without PPTD (mean 3.06+/-2.25 vs. 2.51+/-2.21 pg/mL; p = 0.15). No difference in IL-6 levels was found between the pre- and the postpartum periods (mean 2.67+/-1.82 vs. 3.04+/-2.44 pg/mL; p = 0.30) in all 28 women. Cardiff Study: Serum IL-6 levels were measured on frozen serum samples of 30 women with PPTD. IL-6 levels were below the detection limit (25 fmol/L or 0.65 pg/mL) in 94 (67%) of these samples. No significant difference in the mean serum IL-6 levels were found between any time points in the study. There was no correlation between serum IL-6 levels, thyroid peroxidase (TPO)- antibodies and serum thyrotropin (TSH) levels at any time point. IL-6 levels during pregnancy or postpartum were not found to be significantly different in women with PPTD compared with women without PPTD.

Jejunal mucosal function of the isolated bowel segment created by omentoenteropexy in dogs: a study by in situ luminal perfusion

An isolated bowel segment (IBS) was created in dogs by omentoenteropexy, using staged procedures. (1) Omentoenteropexy was performed at the antimesenteric border of a 15-cm jejunal segment, which was exteriorized at both ends (IBSB). (2) After 6 weeks, once dual vascularization to the IBS had been established, its mesentery was divided (IBSA) or longitudinally split, thus achieving its elongation (IBSE). A control dog underwent a Thiry-Vella (T-V) loop procedure of an identical jejunal segment. Viability of the IBSB and IBSA was previously proven by the authors, through angiographic studies. In the present study, the absorption capability of IBS variants was assessed using in situ luminal perfusion, with a bicarbonate buffer containing glucose and labeled glycine. Jejunal transport rates of these solutes were calculated from the differences in their concentrations in the perfusion solution and in the effluent. Comparisons were made among the IBS variants and between them and the T-V loop. No significant difference in the absorption capability of glucose and glycine was noted between the various IBS variants. There was a marked reduction of glucose absorption and a moderate reduction of glycine absorption in all IBS variants. when compared with the fresh T-V loop, most probably because of disuse atrophy of the mucosa. In conclusion, absorption of glucose and glycine is preserved in the IBS, created by omentoenteropexy, both after its mesenteric division and following the IBS elongating procedure.

Cholestatic pruritus: effect of phototherapy on pruritus and excretion of bile acids in urine

Pruritus associated with hepatic cholestasis may cause significant morbidity and its correlation to retention of bile acids in skin is inconsistent. Available treatment modalities are only partially effective and can have several adverse effects. Phototherapy has recently been reported to improve cholestatic pruritus, but has not been evaluated previously in children, and its mechanism is still unclear. We report the outcome of multiple Daylite phototherapy treatments over two years in a seven-year-old child with chronic hepatic cholestasis that was resistant to other therapeutic modalities. Bile acid levels in urine were used as markers of effectiveness in parallel with clinical response. Night phototherapy alone increased the bile acids/creatinine ratio in urine from 1.54 +/- 0.04 mumol/mg at baseline to 2.07 +/- 0.29 mumol/mg. Continuous phototherapy combined with night diuresis raised the ratio further to 2.28 +/- 0.55 mumol/mg. Night diuresis alone had no effect. Continuous phototherapy combined with night diuresis raised the bile acids/creatinine ratio by 44% on the first day and by 61% on the second day, but declined to baseline on the third day of treatment. A marked clinical improvement was noted for one week following two days of phototherapy. This schedule has been repeatedly effective in improving pruritus for approximately one year and may be due to the ability of phototherapy to enhance excretion of bile acids and other possible pruritogens into urine.

Salt and gastric cancer: a case-control study in Puerto Rico

A total of 136 incident intestinal type gastric cancer cases and 151 age-comparable population controls were interviewed in Puerto Rico about their dietary habits with special emphasis on dietary salt consumption. All interviews were conducted at home using a quantitative dietary frequency instrument. The weekly intake of foods was estimated from the reported frequency of consumption and portion size according to a food model. The dietary salt exposure was estimated from the intake of nine selected food items which are highly salted food items commonly consumed in Puerto Rico. A strong (odds ratio [OR] = 3.34) and statistically significant (P < 0.001) unadjusted difference was found between cases and controls regarding dietary salt exposure. A statistically significant dose response for the index of salt exposure and gastric cancer was also found. The association remained positive and statistically significant after simultaneously adjusting for the confounding effects of sex, education and cigarette smoking.

Effects of hypothyroidism on jejunal mucosal function: study by in situ luminal perfusion in rats

To assess the effects of hypothyroidism (HT) on small-intestinal function, HT was induced in rats (120-150 g) by methimazole in drinking water. After 6 wk of methimazole, intestinal absorption studies were performed in HT and in control (C) rats by in situ luminal perfusion of a 20-cm proximal jejunal loop with a bicarbonate buffer containing sodium, glucose or fructose, glycine or lysine, and phenol red as a nonabsorbable marker for determination of water fluxes. Mucosa from the perfused segment was taken for assay of disaccharidases and ATPases and for light and electron microscopy. Compared with C rats, HT rats had significantly lower jejunal transport rates of water (2.54 +/- 0.36 versus 5.02 +/- 0.7 microL/min/microgram mucosal protein, p < 0.03), sodium (37.1 +/- 10.3 versus 102.7 +/- 18.6 mumol/min/microgram protein, p < 0.05), and glucose (1.49 +/- 0.28 versus 5.17 +/- 0.82 mumol/min/microgram protein, p < 0.02). A reduction in glycine transport was also observed but did not attain statistical significance (p = 0.058). Fructose and lysine transport was unchanged. Mucosal sucrase and lactase activities were similar in both groups, but Na,K-ATPase was significantly lower in HT rats (1.17 +/- 0.3 versus 4.03 +/- 1.5 mumol inorganic phosphate/h/mg protein; p < 0.05), with a diminution of ouabain binding sites by 41.5%. Light microscopy of jejunal mucosa from HT rats did not differ from that from C rats; electron microscopy showed mild mitochondrial swelling in HT enterocytes. A group of HT rats were treated with L-thyroxine during 4 wk; these rats had absorption rates, mucosal enzyme activities, ouabain binding, and mucosal morphology not different from C rats.(ABSTRACT TRUNCATED AT 250 WORDS)

A relationship between circulating natural glucocorticoids and the mechanical responses of the heart in atricial and precocial rodents

1. A comparison was made of the mechanical performance of heart muscle from mouse, an atricial mammal, with corticosterone as glucocorticoid and spiny mouse (Acomys cahirinus), a precocial mammal, with cortisol as glucocorticoid. 2. Force-frequency responses were negative in mouse and positive in spiny mouse. 3. During recovery, there was a gradual increase and an overshoot in the mouse, while in the spiny mouse there was an initial enhanced response, diminishing gradually with time. 4. High calcium concentration inhibited contractile tension in mouse heart, while it was positively inotropic in spiny mouse heart. Changes in the concentration of calcium did not change the patterns of force-frequency response. 5. Lowering the experimental temperature increased the time course and amplitude of the tension curve. However, various parameters exhibited different temperature sensitivity. 6. There was a significant difference in the levels of circulating cortisol between male and female spiny mice. 7. It is proposed that the differences in the mechanical responses of mouse and spiny mouse hearts may be explained in terms of the effects of the specific glucocorticoid hormone on the development of the sodium-calcium exchanger.

Culdoscopic gamete tubal transfer: a new approach to gamete intrafallopian tubal transfer

Twelve infertile couples who failed to conceive by previous infertility treatments and who qualified for culdoscopy had oocyte retrieval and gamete transfer through an operative culdoscopy method. Six patients achieved clinical pregnancy. Five are ongoing pregnancies, and one patient miscarried. There were no complications of the procedures.

Homogeneity and heterogeneity in schizophrenia

This study provides a description of replicated findings of limited heterogeneity in DSM-III schizophrenics. Based now on a sample of 145 schizophrenics, in 1984 and 182 in 1991 it is suggested that the diagnosis is primarily given to chronic patients with poor prognoses, in turn restricting the utility of a process-reactive conceptualization of schizophrenia.

Effect of zinc-deficient diet of varying duration on intestinal disaccharidase activity in the rat

To determine whether zinc has a specific role on weight gain and intestinal disaccharidase activity, 42 male Sprague-Dawley rats were assigned to one of seven groups (n = 6 each). These were a baseline control group (0) that was killed to analyze initial intestinal disaccharidase (sucrase and maltase) activity, a second group (A) fed a zinc-deficient diet for 1 week, a third group (B) pair-fed control for A, a fourth group (C) fed a zinc-deficient diet for 2 weeks, a fifth group (D) pair-fed control for C, a sixth group (E) fed a zinc-deficient diet for 3 weeks, and a seventh group (F) pair-fed control for E. All experimental groups received distilled deionized drinking water, whereas control groups received zinc-enriched (25 micrograms of zinc/ml) distilled deionized water. Water was given ad libitum. After killing, the mucosa of the proximal half of the small intestine was analyzed for protein and disaccharidase activity, and liver, kidney, and heart were analyzed for zinc concentration. Protein content and disaccharidase activity of the jejunal mucosa in the experiment and control groups did not differ significantly. However, animals on the zinc-deficient diet demonstrated mildly depressed growth rates that were proportional to the duration of the experiment, and significantly lower zinc concentration in the kidney in the experimental groups. The data indicate that administration of a zinc-deficient diet for up to 3 weeks did not result in significant changes in intestinal mucosa protein content or in disaccharidase activity.

Non-polar extracts of serum from males contain covert radioimmunoassayable testosterone

Non-polar extracts of sera from human males contain immunoreactive testosterone in a form that is released by mild alkaline hydrolysis. The non-polar derivative shows no immunoreactivity with testosterone antibody prior to hydrolysis. Hydrolyzed non-polar serum extracts from ten adult male volunteers contained 2.0 +/- 0.8 (SD) ng/mL of testosterone. Neither non-polar serum extracts of normal females nor a water blank substituted for non-polar extract of serum yields any immunoreactive testosterone after alkaline hydrolysis. Testosterone palmitate hydrolyzed alone or after addition to non-polar extract of serum yields the expected quantities of radioimmunoassayable testosterone. Previously described conjugates of testosterone are polar and are neither extractable by petroleum ether nor hydrolyzable by alkali. These observations suggest that fatty acid esters of testosterone may be present in serum of human males.

Diminished corticosterone levels in nude mice implanted with MCF-7 or ZR-75-1 human breast tumor cells

Corticosteroid levels were studied in the plasma of athymic mice implanted with human breast tumor cells, either from MCF-7 or ZR-75-1 cell lines. There was a highly significant decrease in plasma corticosterone levels in the mice implanted with these tumor cells. There was no significant effect on corticosterone of GW 39 colon cancer cells, LS 174T colon cancer cells, or Calu-3 lung cancer cells.

Intrafamilial patterns reported by young type A versus type B males and their parents

Retrospective reports regarding parent-child and parent-parent relations during the childrearing years were obtained from adult informants. Male undergraduates typed as As or Bs completed the Clarke Parent/Child Relations Questionnaire augmented with items of likely relevance to A/B. Parallel data were obtained from a subset of subjects' fathers and mothers. Type A and B groups were not different on numerous variables, including parental aggressiveness, vague or escalating standard-setting, or work orientedness. Type A sons were more inclined to view their fathers as attaching great importance to achievement, as setting hard-to-meet expectations, as being unimpressed with son's achievements, and as relating in a competitive way. Differences regarding sons' perceptions of mother were less marked. It is not yet clear to what extent these perceptions (particularly the sons' perceptions of their fathers) are accurate and may thus have played a role in the development of A/B differences, or instead represent a son's judgmental biases associated with his A/B status.

Effect of infusion of bile salts into the mesenteric artery in situ on jejunal mucosal transport function in dogs

We studied the effects of increased circulating levels of bile salts on jejunal mucosal function in dogs. In situ luminal perfusion of a 30-cm proximal jejunal segment was performed while deoxycholate, cholate, taurodeoxycholate, or taurocholate solutions were directly added to the mesenteric arterial supply, reaching the intestinal wall at successive concentrations of 5, 8, 12, and 22 mumol/L. The transport rates of water, sodium, glucose, fructose, glycine, and lysine were measured. The mucosa of the experimental loop was assayed for ATPase activity, and examined by light and electron microscopy. Deoxycholate at 8 microM in the blood supply of the perfused jejunal segment was associated with a significant (p less than 0.02) reduction in the absorption rates of water, sodium, glucose, and glycine, and inhibition of mucosal Na+, K+-ATPase. The absorption of fructose and lysine, and brush border enzyme activities, were not affected. Cholate had a similar effect at 12 microM. There were no obvious histological alterations, but electron microscopy showed swelling of mitochondria in the enterocytes. The reduction in mucosal transport, the inhibition of mucosal Na+, K+-ATPase, and the mitochondrial swelling were reversed after discontinuation of the bile salt infusion. The taurine conjugates at 22 microM depressed transport of water and sodium only, and did not inhibit Na+, K+-ATPase. Our study indicates that increased circulating concentrations of unconjugated bile salts, particularly deoxycholate, may impair Na+, K+-ATPase-related jejunal mucosal function.

Site of zinc absorption in dog small intestine

An in vivo intestinal perfusion technique was used to study the absorption of zinc from the duodenum, proximal jejunum and distal ileum of six dogs (group 1). Net absorption of zinc from the duodenum before and after ligation of the common bile duct averaged 596 and 574 ng.min-1.cm-1, respectively. Zinc absorption was greater (P less than 0.01) from the duodenum than from the jejunum (251 ng.min-1.cm-1) or ileum (404 ng.min-1.cm-1). Four other dogs (group 2) experienced perfusion of approximately equal segments of the duodenum (in two animals the common bile duct was ligated, and in another two it was not), proximal jejunum and distal ileum for 4 h. No change in absorption of zinc with time was noted, nor was any difference in absorption by the duodenum with and without ligation of the common bile duct observed. The data indicate that the duodenum has the greatest capacity for zinc absorption, followed by the distal ileum and proximal jejunum, and that pancreatic secretions do not appear to be necessary for adequate zinc absorption in the dog duodenum.

Prostatic ejaculate in assigned males with 46,XX congenital adrenal hyperplasia

Two assigned males with 46,XX congenital virilizing adrenal hyperplasia due to 11 beta-hydroxylase deficiency reported an ejaculation of thick fluid. Chemical analysis revealed that the fluids bore a resemblance to normal prostatic fluids. Extreme virilization in utero seems to have produced both complete virilization of external genitalia and development of a prostate.

Effects of nonischemic hypoxia on jejunal mucosal structure and function: study of an experimental model in dogs

A model of nonischemic hypoxia of the jejunum was designed in dogs, by shunting of blood from the inferior vena cava directly into the regional mesenteric arterial supply, thereby lowering the PaO2 of the blood that reached the jejunal wall from 98.6 +/- 3 to 62 +/- 5 mm Hg. Absorption rates of sodium, glucose, fructose, glycine, and the dibasic aminoacid lysine were studied by in situ luminal perfusion of a 30-cm proximal jejunal segment with a bicarbonate buffer solution containing phenol red as a nonabsorbable marker for determination of water fluxes. During periods of control, hypoxia, and after discontinuation of the venoarterial admixture (recovery), effluent perfusate was collected and mucosal biopsies were obtained for assay of lactase, maltase and sucrase activity, mucosal ATPase activity and ATP content, and for light- and electron microscopic examination. Mesenteric supply with hypoxic blood was associated with a significant inhibition of Na+,K+-ATPase activity (p less than 0.001) and a rise in mucosal ATP content (p less than 0.05). There was a significant reduction in the absorption rates of sodium (p less than 0.001), glucose, and glycine (p less than 0.01), but no change in the transport of fructose and of lysine. Brush border enzymes were unaltered. The histological appearance of the mucosa remained normal throughout the experiment, but on electron microscopy a distinct swelling of the enterocyte mitochondria was noted during the hypoxia period.(ABSTRACT TRUNCATED AT 250 WORDS)

Unconjugated hyperbilirubinaemia in hypertrophic pyloric stenosis, an enigma

In a search of features that might be relevant to the understanding of the hyperbilirubinaemia of infants with hypertrophic pyloric stenosis (HPS), we examined the duodenal fluid in 11 infants with this condition. Four (36%) had an unconjugated bilirubin level above 2.5 mg/dl in the serum. Levels of electrolytes, bicarbonate, liver function tests and cholesterol were similar in the jaundiced and the non-icteric infants. Examination of duodenal fluid for pH, concentration of bilirubin, bile salts, electrolytes and beta-glucuronidase levels also did not disclose any significant differences between the HPS patients and the controls. Bacterial culture of the fluid yielded similar results in both groups. We may conclude that the unconjugated hyperbilirubinaemia observed in some patients with HPS is not associated with overgrowth of bacteria, changes in glucuronidase levels, pH, electrolytes or biliary obstruction.

Occurrence of cancer in women in the meat industry

A follow up study of 7261 white women from a meatcutters' union was conducted between July 1949 and December 1980. Proportional mortality ratio (PMR) and standardised mortality ratio (SMR) analyses, using the United States general population mortality rates, were conducted for the group as a whole and for subgroups defined according to the four main job categories in the meat industry, and a fifth category of workers from outside the industry but belonging to the same union (control group). At least a threefold risk of death was observed both for myeloid leukaemia and non-Hodgkin's lymphomas among workers in the meat department of retail food stores. No excess risk from these diseases was observed in the control group. SMRs of 4.56, 4.02, and 1.95, which were statistically significant, were observed for lung cancer among workers in chicken slaughtering plants, meatpacking plants, and retail food stores respectively. The lung cancer SMR for abattoir workers was 1.41 (not significant) and 1.11 for workers in non-meat companies. The role of potentially harmful exposures within the industry in the occurrence of these excesses is discussed.

Cancer mortality among white males in the meat industry

A study was conducted among 13,844 members of a meat-cutter's union, from July 1949 to December 1980, to examine cancer occurrence in the meat industry. Separate analyses were carried out for the whole group, and for subgroups defined by job-categories characteristic of the industry, including a control group. Mortality was compared with that of the United States through the estimation of standardized mortality ratios (SMR) and proportional mortality ratios. A statistically significant proportional mortality ratio of 2.9 was obtained for Hodgkin's disease among abattoir workers; the SMR of 2.2 was not significant. Among meat-packing plant workers, highly statistically significant SMRs were recorded for bone cancer, SMR = 9.6; cancer of the buccal cavity and pharynx, SMR = 3.4; and lung cancer, SMR = 1.9. The role of oncogenic viruses and other carcinogenic exposures was investigated.

Effect of metabolic acidosis upon sleep apnea

The effects of metabolic acidosis upon the pattern of apnea during sleep were assessed in ten sleep apnea patients. Four had pure obstructive apnea, two pure central apnea, and four had mixed apnea. Acidosis was induced with acetazolamide. Acid-base shifts had little effect in pure obstructive and pure central apnea, but had a significant effect in mixed apnea. In two of the mixed apneic patients, metabolic acidosis converted predominantly central apnea into nearly pure obstructive apnea, prolonging apneic periods and worsening hypoxemia. A suggested explanation for this is the greater stimulating effect of acidosis upon the lower bellows muscles than upon the muscles which act to maintain patency of the upper airways. The observation that some patients with mixed sleep apnea appear to have central apnea while relatively alkalotic and obstructive apnea while acidotic emphasizes the need for more careful and detailed characterization of apneic disorders with respect to their responses to body states and therapeutic agents.

Excretory pattern of bile during phototherapy

We studied the acute effects of phototherapy (PT) on bile flow and on the biliary excretion of bilirubin pigments and of bile salts in male homozygous Gunn rats (120-150 g). 13 rats received PT and 10 rats were kept in the dark. Bile was collected by cannulation of the common bile duct at hourly intervals from 1 h prior to PT till after 4 h of 'lights on'. Before treatment, all values were similar in both groups. After 4 h of lights on, mean plasma bilirubin fell from 145.3 +/- 4.3 to 99.2 +/- 2.7 mumol/l (p less than 0.01) in the PT rats, but did not change in the controls. During the lights-on period, PT rats had a significantly higher hourly bile volume, and a higher excretion of biliary bilirubin and bile salts than the controls (p less than 0.005). Over the total 4-hour lights-on period, the PT group had a higher mean output of bile than the controls (0.93 +/- 0.17 vs. 1.52 +/- 0.34 ml/4 h; p less than 0.005) and an increased excretion of bilirubin (0.08 +/- 0.016 vs. 0.148 +/- 0.01 mumol/4 h; p less than 0.005) and bile salts (35.1 +/- 3.7 vs. 55.2 +/- 12.5 mumol/4 h; p less than 0.005). The results show that PT of the Gunn rat is associated with a rise in bile flow and with an increased excretion of bile salts, in addition to an increased biliary bilirubin output.

Phototherapy-associated diarrhea. The role of bile salts

The concentration of fecal bile salts was measured in 14 jaundiced neonates who received phototherapy (PT group) and their 14 nontreated matched controls (C). Before initiation of phototherapy, mean bile salt concentrations in stool specimens from the two groups were similar. At 12 hours of 'lights on', stool specimens from PT babies showed a significantly increased mean bile salt concentration, whereas in the C babies there was no change (3.65 +/- 0.39 vs 2.62 +/- 0.22 mmol/l; p less than 0.01). At 24 hours after 'lights off', stool specimens from the PT infants had a mean bile salt concentration like that before phototherapy, and not different from C. During phototherapy, nine PT babies had a bile salt concentration in their stools of 3.5 mmol/l and above; 6 of these babies had watery stools with a high sodium content. The high concentration of bile salts found in the colonic contents of neonates during phototherapy would appear to be a factor in the pathogenesis of phototherapy-associated diarrhea in the jaundiced neonate.

The sudden infant death syndrome and apnea/obstruction during neonatal sleep and feeding

Respiratory observations made during nutritive feeding and a complete daytime nap within the first week of life on ten newborns who subsequently were victims of sudden infant death syndrome (SIDS) were compared with normative data based on 1,301 infants of comparable ages. Measurements were obtained of all apneic pauses and/or transient respiratory obstructive events at least two seconds in duration. A statistically significant increased number of future SIDS victims were found to have an unusual amount of apnea/obstruction episodes during nutritive feeding when compared with the normative group. Future SIDS victims, as a group, also had an increased frequency of apneic pauses during sleep. Furthermore, all SIDS victims demonstrated either an unusual amount of apnea/obstruction during nutritive feeding or apneic pauses during sleep. None of the airway obstruction measures during sleep differentiated the SIDS infants from the normative group. These results are consistent with the general hypothesis that prolonged apnea or airway obstruction is part of the pathophysiologic process resulting in SIDS and those hypotheses implicating unstable respiratory activity during sleep as well as apnea and pharyngeal/laryngeal dysfunction induced by liquid stimulation of the upper airway. They are also compatible with the growing body of evidence indicating that factors that predispose an infant to SIDS originate in the perinatal period.

Biochemical screening for inherited metabolic disorders in the mentally retarded

A biochemical screening programme for the detection of inherited metabolic disease was carried out on urine and blood samples from inmates of the Alexandra Institute for the mentally retarded, Cape Town. Of the 1087 patients screened, positive results for phenylketonuria were obtained in 3, for cystinuria in 2 and for Hartnup disease in 1. The overall frequency of metabolic disorders was 0,6%. It is evident that genetic metabolic disease as detected by current screening procedures makes only a small contribution to the overall burden of mental retardation.

A comparison of gross and microsurgical techniques for repair of cornual occlusion in infertility: a retrospective study, 1968-1978

A 10-year experience is recounted moving from traditional gross implantation methods to microsurgical anastomosis in the repair of cornual occlusion in infertility. Two gross surgical implantation techniques, one involving reaming out the intramural portion of the uterine tube and the other dissecting it out via a transfundal incision, are compared with microsurgical uterotubal anastomosis. The author reports a 4.7 times improvement in the term pregnancy rate after turning to microsurgery and describes his method for anastomosing the transected ampulla or isthmus to the intramural portion of the tube.