Adrenocortical carcinoma presenting with heterosexual pseudoprecocious puberty shortly after birth: case report and review

Adrenocortical tumour is rare in children. We report on a female infant with adrenocortical carcinoma presenting with pseudoprecocious puberty at the age of two. She had a history of gradually increasing public hair growth after birth. Physical examination showed signs of virilisation such as pubic hair growth and hirsutism with evidence of facial hair growth. On biochemical evaluation, DHEA-S, 17-OH progesterone, and testosterone levels were elevated. An abdominopelvic spiral computed tomography (CT) scan with intravenous contrast identified a well-defined heterogeneously enhanced mass with areas of necrosis in the right adrenal gland and downward displacement of the underlying kidney. There was no evidence of distant metastasis on CT imaging. An exploratory laparotomy was performed in which a large, haemorrhagic and necrotic mass in the right adrenal gland with pressure effect on right liver lobe and signs of thrombosis in the inferior vena cava was detected. Pathologic examination confirmed the adrenocortical carcinoma. She received eight cycles of adjuvant chemotherapy with Carboplatin, Etoposide, and Doxorubicin regimens and underwent follow-up visits thereafter in which no sign of recurrence was observed. In conclusion, adrenocortical carcinomas are rare in children, but they should be considered in any child presenting with signs of pseudoprecocious puberty.

A review of experimental and modeling techniques to determine properties of biopolymer-based nanocomposites

The nonbiodegradable and nonrenewable nature of plastic packaging has led to a renewed interest in packaging materials based on bio-nanocomposites (biopolymer matrix reinforced with nanoparticles such as layered silicates). One of the reasons for unique properties of bio-nanocomposites is the difference in physics at nanoscale as compared to that at macroscale. Therefore, the effect of nanoscale on the properties of bio-nanocomposites is discussed. Properties of bio-nanocomposites are governed by the extent of dispersion of nanoparticles in the biopolymer matrix and interaction between nanoparticles and the biopolymer. Selection of proper technique to determine properties of these bio-nanocomposites is very critical in assessing their performance. Experimental techniques (tensile testing, barrier property measurement, dynamic mechanical analysis, differential scanning calorimetry, thermogravimetric analysis, rheological measurement) to determine the mechanical, barrier, thermal, and rheological properties of bio-nanocomposites are discussed in terms of methodology, interpretation of results, and application in studying the properties of bio-nanocomposites. Mathematical modeling plays an important role in predicting the properties of bio-nanocomposites and comparing them to the measured properties. This comparison helps in better understanding the mechanism for much improved properties of bio-nanocomposites. Mathematical modeling is also helpful in understanding the effects of different parameters on the properties of bio-nanocomposites. Therefore, the article describes mathematical modeling of mechanical and barrier properties of bio-nanocomposites using analytical micromechanics.

Effect of type and content of modified montmorillonite on the structure and properties of bio-nanocomposite films based on soy protein isolate and montmorillonite

The nonbiodegradable and nonrenewable nature of plastic packaging has led to a renewed interest in packaging materials based on bio-nanocomposites (biopolymer matrix reinforced with nanoparticles such as layered silicates). Bio-nanocomposite films based on soy protein isolate (SPI) and modified montmorillonite (MMT) were prepared using melt extrusion. The effect of different type (Cloisite 20A and Cloisite 30B) and content (0% to 15%) of modified MMT on the structure (degree of intercalation and exfoliation) and properties (color, mechanical, dynamic mechanical, thermal stability, and water vapor permeability) of SPI-MMT bio-nanocomposite films were investigated. Extrusion of SPI and modified MMTs resulted in bio-nanocomposites with exfoliated structures at lower MMT content (5%). At higher MMT content (15%), the structure of bio-nanocomposites ranged from intercalated for Cloisite 20A to disordered intercalated for Cloisite 30B. At an MMT content of 5%, bio-nanocomposite films based on modified MMTs (Cloisite 20A and Cloisite 30B) had better mechanical (tensile strength and percent elongation at break), dynamic mechanical (glass transition temperature and storage modulus), and water barrier properties as compared to those based on natural MMT (Cloisite Na(+)). Bio-nanocomposite films based on 10% Cloisite 30B had mechanical properties comparable to those of some of the plastics that are currently used in food packaging applications. However, much higher WVP values of these films as compared to those of existing plastics might limit the application of these films to packaging of high moisture foods such as fresh fruits and vegetables.

A novel RAB27A mutation in a patient with Griscelli syndrome type 2

Griscelli syndrome type 2 is a rare autosomal recessive primary immunodeficiency disease caused by a mutation in the RAB27A gene and characterized by oculocutaneous hypopigmentation and variable cellular immunodeficiency. We report the case of a 6-month-old infant with silvery hair, eyelashes, and eyebrows who was referred to our center because of fever and hepatosplenomegaly. Bone marrow studies indicated hemophagocytosis, whilst microscopic examination of the hair showed irregular agglomerations of pigment in hair shafts. Molecular analysis revealed a novel homozygous mutation in exon 5, namely, a single-base substitution (g.42996 A>G) leading to an amino acid change (S115G) and thus confirming the diagnosis of Griscelli syndrome type 2. Griscelli syndrome could be more common than thought, especially in regions with high rates of consanguinity. As the prognosis of disease is usually poor, prompt diagnosis and appropriate treatment are vital to avoid complications.

Can total and transition zone volume of the prostate determine whether to perform a repeat biopsy?

OBJECTIVES

To compare the ability of total prostate (TP) and transition zone (TZ) volume to predict the outcome of a repeat prostate biopsy in patients with serum prostate-specific antigen (PSA) levels of 4 to 10 ng/mL.

METHODS

A total of 1137 patients were included and underwent transrectal ultrasound-guided needle sextant and two transition zone biopsies of the prostate. All patients with a prior negative biopsy (benign prostatic tissue) underwent a repeat biopsy after 6 weeks. The TP and TZ volumes of the prostate were measured by transrectal ultrasonography.

RESULTS

Of the 1137 patients, prostate cancer was diagnosed in 364 (32%), in 276 (24.2%) after the first biopsy and in 88 (7.7%) after the repeated biopsy. The TP and TZ volumes were larger in the patients with prostate cancer detected on the repeated biopsy (P <0.0001). Using a cutoff for TP volume of less than 20 cm3 and greater than 80 cm3 and for TZ volume of less than 9 cm3 and greater than 41 cm3 would have spared 7.1% and 10% of repeated biopsies, respectively.

CONCLUSIONS

The probability for a positive repeat prostate biopsy increases in a logarithmic function for larger prostates, as well as for larger TP and, especially, for larger TZ volumes. The probability of finding prostate cancer on a repeat biopsy in prostates with small (less than 20 cm3) and large (greater than 79 cm3) TP, as well as in small (less than 9.3 cm3) and large (greater than 41 cm3) TZ volumes, was very low. Therefore, a repeat prostate biopsy within 6 weeks is unnecessary. These patients should be followed up by serial PSA determination.

Controlling organic reactions on silicon surfaces with a scanning tunneling microscope: theoretical and experimental studies of resonance-mediated desorption

The dynamics of tip-induced, resonance-mediated bond-breaking in complex organic adsorbates is studied theoretically and experimentally. Desorption of benzene from a Si(100) surface is found to be efficient and sensitive to voltage, the measured yield rising from below 10(-10) to ca. 10(-6) per electron within a ca. 0.8 V range at low (< 100 pA) current. A theoretical model, based upon first principles electronic structure calculations and quantum mechanical wavepacket simulations, traces these observations to multi-mode dynamics triggered by a transition into a cationic resonance. The model is generalized to provide understanding of, and suggest a means of control over, the behaviour of different classes of organic adsorbates under tunneling current.

Adenoid cystic carcinoma of the base of the tongue

A retrospective review of 14 patients with adenoid cystic carcinoma of the tongue treated between 1955 and 1997 was performed. Treatment consisted of surgery (n = 2), radiotherapy (n = 2), chemotherapy (n = 1), or combination therapy (n = 9). The 2-, 5-, and 10-year absolute survival rates were 92%, 79%, and 63%, respectively. Seventy-five percent of the patients who died of cancer succumbed to distant metastases. However, long-term survival was common despite a high incidence of local and distant recurrence. The presence of positive surgical margins, the incidence of regional metastases, the incidence of perineural invasion, the initial stage of disease, and the eventual development of locoregional recurrence and distant metastases did not significantly alter the survival rate. Surgical extirpation combined with postoperative radiotherapy is advocated for the treatment of adenoid cystic carcinoma of the tongue. Given the indolent nature of this disease process, surgery should be directed toward conservation of speech and swallowing function.

The role of hyperplasia in multiple parathyroid adenomas

BACKGROUND

Parathyroid adenoma is the most common cause of primary hyperparathyroidism (pHPT). Adenomas usually involve only a single gland, and the remaining glands are normal or suppressed. Multiple parathyroid adenomas have been reported to occur in as high as 11% of patients with pHPT. The significant incidence of multiple adenomas with histologic similarities to hyperplasia has raised the possibility that adenoma is a continuation of the hyperplasia state. To test this theory, we used molecular genetics to compare clonality and proliferative activity of parathyroid adenoma with its corresponding normal glandular tissue. Furthermore, we devised a scheme to definitively distinguish between the different parathyroid states on a molecular level, because histologic distinction is unreliable.

METHODS

The study included three patients with a diagnosis of singular parathyroid adenoma and three with double parathyroid adenomas. Paraffin-embedded surgical specimens of both adenomas and normal glands were retrieved from each patient. Clonal analysis of the phosphoglycerolkinase (PGK) gene has suggested that parathyroid adenomas are monoclonal. Clonality of parathyroid adenomas and normal parathyroid glands was studied by polymerase chain reaction-based restriction fragment length polymorphic analysis for the PGK gene. Proliferative activity of the specimens was also analyzed using the immunohistochemical markers PCNA and Ki-67.

RESULTS

All adenomas were monoclonal and all normal parathyroid glands were polyclonal for the PGK gene in both the single and double adenoma specimens. All adenomas stained positive for proliferative activity. In the three patients with singular adenoma, proliferative activity was not detected in the normal parathyroid tissue. However, in the double adenoma group, two of the three patients showed hyperproliferative activity in the normal glands.

CONCLUSION

Proliferative activity consistent with hyperplasia was present in some normal glands of multiple adenoma patients. Our observation supports the theory that multiple adenomas may be a continuation of the hyperplasia state.

Twelve-year experience with two courses of adjuvant single-agent carboplatin therapy for clinical stage I seminoma

PURPOSE

During the past 30 years, radiation therapy with 28 to 30 Gy for para-aortic and ipsilateral iliac node areas was the standard adjuvant treatment for clinical stage I seminoma after orchiectomy. However, late effects of radiotherapy prompted a search for alternative adjuvant treatment approaches, including surveillance and application of carboplatin. In this retrospective analysis, we evaluated the efficacy and toxicity of two adjuvant single-agent carboplatin courses in 107 patients who were diagnosed with clinical stage I seminoma at our study centers between 1988 and 1999.

PATIENTS AND METHODS

All 107 patients (median age, 39 years; range, 24 to 63 years) received two postoperative adjuvant cycles of carboplatin (400 mg/m(2)). The pathologic tumor stage was pT1 in 84 patients, pT2 in 18 patients, and pT3 in five patients. Whole blood count and serum chemistry were evaluated weekly during treatment to assess hematologic and nonhematologic toxicity.

RESULTS

Six patients died from tumor-unrelated causes. The remaining 101 patients are currently alive and free of disease after a median follow-up of 74 months (range, 5 to 145 months). A detailed analysis of hematologic toxicity showed only World Health Organization (WHO) grade 1 leukocytopenia in 10.7% of all cycles and WHO grade 2 leukocytopenia in 2.1% of all cycles.

CONCLUSION

Regarding the absence of tumor recurrences in our retrospective analysis and the favorable toxicity profile with no episodes of long-term toxicity, we suggest that two adjuvant courses of single-agent carboplatin for clinical stage I seminoma patients might be equivalent to radiotherapy.

Inducing desorption of organic molecules with a scanning tunneling microscope: theory and experiments

A scanning-tunneling microscope has been used to induce efficient local desorption of benzene from Si(100) at low currents (<100 pA), sample biases (approximately -2.4 V) and temperatures (22 K). A theoretical model based upon first principles electronic structure calculations and quantum mechanical wave packet dynamics describes this process as occurring via transient ionization of a pi state of the adsorbed molecule. This model accounts for the unexpected efficiency and sharp threshold of the yield.

Microwave thermotherapy in patients with chronic urinary retention

PURPOSE

To evaluate the efficacy of high-energy transurethral microwave thermotherapy (TUMT) in the treatment of chronic urinary retention (CUR) due to benign prostatic hyperplasia (BPH).

MATERIALS AND METHODS

In this prospective cohort study, 29 patients with CUR due to BPH underwent high-energy TUMT. Prior to treatment and during a 12-week follow-up, the following parameters were determined: quality of life (QOL) score, peak flow rate (Qmax) by uroflowmetry, and postvoid residual urine (PVR). In those with treatment failure (PVR > 150 mL or urinary retention), pressure-flow studies were performed and compared to pre-TUMT urodynamics.

RESULTS

Of the 29 patients, 21 (72%) regained the ability to void spontaneously at 5 weeks. The actuarial median time for spontaneous voiding to be restored was 3.5 weeks (95% confidence interval [CI] 2.9-4.8 weeks). Mean QOL score at 12 weeks post-TUMT (2.2; 95% CI 1.5-2.7) was lower than that at 1 week (4.6; 95% CI 3.9-5.8) by 51% (p < 0.0005). Further, a 55% increase in mean Qmax (p < .0005) determined by uroflowmetry was observed by 12 weeks vs. 1 week after high-energy TUMT. TUMT failed in 8 patients due to a hypocontractile detrusor.

CONCLUSIONS

We concluded that high-energy TUMT is a potentially useful option for patient with CUR who are not candidates for prostatectomy.

Third branchial cleft anomaly presenting as a retropharyngeal abscess

Branchial cleft anomalies are congenital developmental defects that typically present as a soft fluctuant mass or fistulous tract along the anterior border of the sternocleidomastoid muscle. However, branchial anomalies can manifest atypically, presenting diagnostic and therapeutic challenges. Error or delay in diagnosis can lead to complications, recurrences, and even life-threatening emergencies. We describe a case of an infected branchial cleft cyst that progressed to a retropharyngeal abscess in a 5-week-old female patient. The clinical, radiographic, and histologic findings of this rare presentation of branchial cleft cyst are discussed.