Access Technique for Retroperitoneoscopy

Purpose

The access technique for retroperitoneoscopy is not well established, and differs from transperitoneal laparoscopic access in 3 key aspects: 1) location and technique of primary trocar placement, 2) optimal positioning of the balloon dilator and 3) technique for safe placement of secondary ports. Our method of obtaining retroperitoneoscopic access addresses these issues.

Materials and Methods

A total of 37 patients underwent retroperitoneoscopic surgery of the kidney and upper ureter.

Results

Our technique facilitates balloon placement within Gerota's fascia, minimizes peritoneal injury and optimizes port placement during retroperitoneoscopic surgery.

Conclusions

Although our success rate for placing the balloon within Gerota's fascia has improved, additional experience is required to achieve subfascial balloon placement more consistently.     

Molecular diagnosis of exocrine pancreatic cancer using a percutaneous technique

Background: The K-ras oncogene is activated by point mutations at codon 12 in most patients with exocrine pancreatic cancer. Mutant-enriched polymerase chain reaction (PCR) amplification can enhance the detection of mutated K-ras. This technique was applied to patients undergoing percutaneous fine-needle aspiration (FNA) biopsy of suspect pancreatic lesions. Methods: Twenty-five patients underwent percutaneous FNA of the pancreas for cytologic and molecular analysis. After preparing cytologic smears, the 22-gauge needle and syringe used for FNA were rinsed in RPMI-1640. The specimen was centrifuged, and DNA was extracted from the supernatant and subjected to mutant-enriched PCR using appropriate mismatched primers that introduce a BstNI restriction endonuclease cleavage site at codon 12 of wild-type, but not mutant, K-ras. After digestion with BstNI, the DNA was reamplified. To increase assay sensitivity, the final five PCR cycles were completed incorporating 5 μCi of (α-32P)dCTP. The DNA was then redigested and subjected to gel electrophoresis and autoradiography. Results: The median amount of DNA retrieved per specimen was 3.33 μg. Mutant K-ras was detected as a band of 143 bps; residual wild-type DNA was seen as a 114-bp fragment. Twenty-one of 25 specimens demonstrated mutated K-ras DNA. Two patients with nondiagnostic cytology results had mutated K-ras DNA; adenocarcinoma of pancreatic origin was confirmed in both cases after pancreatectomy. Conclusion: The molecular diagnosis of pancreatic cancer through identification of mutations in K-ras can be readily performed on specimens obtained by percutaneous FNA. As aggressive multimodality management of this disease becomes more common, pretreatment analysis of molecular determinants may have greater clinical significance. Presented at the 48th Cancer Symposium of The Society of Surgical Oncology, Boston, Massachusetts, March 23–26, 1995.     

Involvement of norepinephrine in startle arousal after acute and chronic d-amphetamine administration

Treatment with d-amphetamine produced a dose-dependent increase in startle amplitude in response to a buzzer. This increase appeared to be a reflection of a sensitization effect, i.e., enhanced responsivity as a function of repeated stimulus presentations. Treatment with -methyl-p-tyrosine, which reduced whole brain concentrations of dopamine (DA) and norepinephrine (NE), or treatment with FLA-63, which reduced only NE, antagonized the effects of d-amphetamine on the startle reflex, suggesting a role of NE in this behavior. Startle amplitude was also reduced following chronic d-amphetamine treatment. The effect of d-amphetamine on startle was found to be independent of changes in drug-induced locomotor excitation. The data of the present investigation, together with earlier reports, suggests that tolerance occurs to those behaviors that involve a noradrenergic component.     

Response sensitization and depression following long-term amphetamine treatment in a self-stimulation paradigm

The effects of long-term amphetamine treatment were evaluated on responding supported by self-stimulation of the substantia nigra. Rats repeatedly treated with d-amphetamine, and tested with a low dose of the drug that ordinarily has no behavioral effect, showed higher response rates than animals repeatedly treated with saline and tested with the same dose of amphetamine. In contrast, a depression in responding was observed among animals that received long-term amphetamine administration and were tested with saline. The effects of long-term amphetamine treatment on self-stimulation could not be explained by the intrusion of drug-induced competitive behaviors such as locomotor activity and stereotypy. The results were attributed to changes in dopamine neurotransmission following prolonged exposure to amphetamine and were also discussed in terms of an animal model for amphetamine psychosis and postamphetamine depression in man.     

Transthyretin is an inhibitor of monocyte and endothelial cell interleukin-1 production

Human serurn was found to contain an inhibitor of constitutive interleukin 1 (IL-1) production by human umbilical vein endothelial cells (ECs). Purification of the serum activity by anion exchange chromatography, molecular sieve HPLC, and hydroxyl apatite chromntography yielded material 82% pure with a molecular weight of 17 kDa by SDS-PAGE. Amino acid sequencing revealed the purified inhibitor to be transthyretin (TTR). a liver-derived protein. There was a 42.6% reduction in the production of spontaneous IL-1 activity in EC supernatants after coculture with 10g/ml TTR. TTR was subsequently found by ELISA to inhibit LPS-stimulated IL-1 production by cells of the human monocytic leukemia line THP-1 by 47.1 ± 9.4%, whereas a less striking but still significant inhibition of monocyte-derived IL-1 production was also observed. Inhibition of IL-1 secretion correlated with increased IL-1 mRNA synthesis in both THP-1 cells and monocytes. Furthermore, TTR was associated with increased intracellulaf concentrations of IL-1. These data suggest that TTR functions by inhibiting processing of newly synthesized peptide for secretion. This novel inhibitory effect of TTR on the production of IL-1 activity suggests a previously unrecognized endogenous antiinflammatory mediator.     

Two arcane areas in liposuction: The banana and the sensuous triangle

Two new approaches in suction lipectomy of the buttocks region are described: liposuction of the banana and liposuction of the sensuous triangle. The banana is the highest part of the posterior thigh just below the buttocks crease. It appears only in certain individuals and appears as a buldge under the buttocks crease. The preferred approach to liposuction of the banana is discussed as well as a theory as to its etiology. A common complication of liposuction of this area is ptosis of the buttocks crease. Methods of treatment of this complication are also discussed. The second topic addressed is liposuction of the sensuous triangle which is at the junction of the lateral buttocks, lateral thigh, and posterior thigh. The result of suctioning this area is a more athletic-appearing buttocks region.Presented at the 7th Annual Meeting of the Lipoplasty Society of North America, San Francisco, California, October 29, 1989     

Monoaminergic-cholinergic relationships and the chemical communication matrix of the substantia nigra and neostriatum

The historical development of histochemical methods for monoamines and chemicals involved with cholinergic function is reviewed. The use of these methods to elucidate neurochemical interactions in the substantia nigra and caudate-putamen complex is then discussed. Three hypotheses accounting for the localization of acetylcholinesterase within and/or on substantia nigra, pars compacta neurons are presented and evaluated:

1. (a) to catabolize acetylcholine released from afferent cholinergic fibers,

2. (b) to catabolize substance P released from some neostriato-nigral axon terminals, and/or

3. (c) to serve as a communication link with nigral vasculature.

Despite experimental evidence in favor of each of these possibilities, none have met with unqualified acceptance. Possible mechanisms and morphologic substrates accounting for dopaminergic-cholinergic, serotonergic-cholinergic, GABAergic-cholinergic, enkephalinergic-cholinergic, and cholinergic-cholinergic interactions in the caudate-putamen complex are discussed. These include synaptic and non-synaptic relationships, dendroaxonic information flow, and mutual regulatory processes.

Combination chemotherapy of the epipodophyllotoxin derivatives,Teniposide and Etoposide

Summary Previous studies in vitro on the influence of extracellular protein binding of Teniposide (VM26) and Etoposide (VP16-213) on subsequent cellular uptake by experimental murine tumor cells [Cancer Res 38: 2549 (1978); Drug Metab Rev 8: 119 (1978)] suggested that a timed-sequential combination of VM26 and VP16-213 may increase the bioavailability of VP16-213. This was studied clinically in six cancer patients with ascites (five ovarian, one rectal) whereby VM26 (20 mg/m²) was given i.p. 2 h prior to VP16-213 (100 mg/m²; i.p.). In some patients, this regimen was administered i.v. The i.v. regimen was found to be more toxic (myelosuppression, nausea, vomiting) than i.p. regimen at same doses of drugs. Several patients remained stable to disease during 1–2 courses of therapy (3 weeks per course), one patient had partial remission, and has been stable in her disease for more than 4 months.In two patients, plasma and ascites fluid was analyzed for VP16-213 and VM26 by a new reverse-phase high performance liquid chromatography method. Both VM26 and VP16-213 could be eluted isocratically (28% v/v acetonitrile in water) from a c₁₈ column with retention times of 6.6 and 13.3 min, respectively. Subsequent pharmacokinetic analysis of one patient suggests that protein binding displacement of VP16-213 in plasma and perhaps ascites fluid increased the pharmacokinetic volume of distribution (28 l) and reduced the elimination half-life (12 h). The data suggests that VP16-213 is distributed more widely in the body and is represented by a single compartment pharmacokinetic model. Analysis of VM26 in ascites and plasma suggests that the so-called deep pharmacokinetic compartment represents ascites equivalent space and that the plasma concentration represents VM26 as free and protein-bound drug in kinetic distinguishable compartments.Determinants of drug action are potentially composed of a multiplicity of physiological, biochemical, and other factors. The potential for manipulating the pharmacodynamic properties of drugs to achieve greater therapeutic potential needs further study.     

Circling behavior following systemic d-amphetamine administration: Potential noradrenergic and dopaminergic involvement

Systemic treatment with d-amphetamine produced a dose-dependent increase in the circling behavior of normal mice. Treatment with both -methyl-p-tyrosine (-MpT) and FLA-63 antagonized the amphetamine-induced circling behavior. Similarly, blockade of B-adrenergic receptors by propranolol and dopamine receptors by haloperidol reversed the circling response elicited by amphetamine. In contrast to -MpT and haloperidol, however, neither FLA-63 nor propranolol attenuated the locomotor excitation engendered by amphetamine. Following repeated d-amphetamine injections the circling ordinarily induced by a single injection was abolished, whereas the locomotor effects of amphetamine remained unaltered. These findings are consistent with earlier work suggesting that tolerance may occur in those behaviors that involve a noradrenergic component.     

Comorbid medical illness in psychiatric patients

Patients with psychiatric illnesses may be at higher risk for the development of certain medical problems. Those with more severe psychiatric illnesses may encounter barriers to promoting good health and to obtaining good health care when comorbid illnesses do occur. This paper reviews some of the recent literature on health care practices and health system access for the mentally ill; HIV care and its relationship to mental disorders; drug interactions between general medical drugs and psychotropics; and certain medical conditions that appear to co-occur more frequently with psychiatric disorders.